UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549


                                    FORM 11-K

              / x / ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE
                         SECURITIES EXCHANGE ACT OF 1934

                   For the fiscal year ended December 31, 2003

                                       OR

             / / TRANSITION REPORT PURSUANT TO SECTION 15(d) OF THE
                         SECURITIES EXCHANGE ACT OF 1934

              For the transition period from _________ to _________

                        Commission File Number: 333-39249

       A.   Full title of the plan and the address of the plan, if different
            from that of the issuer named below:

          PIONEER NATURAL RESOURCES USA, INC. 401(k) AND MATCHING PLAN


       B.   Name of issuer of the securities held pursuant to the plan and the
            address of its principal executive office:

                        Pioneer Natural Resources Company
                      5205 North O'Connor Blvd., Suite 900
                               Irving, Texas 75039







          PIONEER NATURAL RESOURCES USA, INC. 401(k) AND MATCHING PLAN


                 Financial Statements and Supplemental Schedule

    As of December 31, 2003 and 2002 and for the year ended December 31, 2003

          With Report of Independent Registered Public Accounting Firm



                                       2











          PIONEER NATURAL RESOURCES USA, INC. 401(k) AND MATCHING PLAN




                                Table of Contents


                                                                        Page


Report of Independent Registered Public Accounting Firm ...........       4

Statements of Net Assets Available for Benefits as of
   December 31, 2003 and 2002......................................       5

Statement of Changes in Net Assets Available for Benefits
   for the year ended December 31, 2003............................       6

Notes to Financial Statements......................................       7

Schedule H; Line 4i - Schedule of Assets (Held At End of Year)
   as of December 31, 2003.........................................      13

Signatures.........................................................      14

Index to Exhibits..................................................      15


                                       3














             Report of Independent Registered Public Accounting Firm


To the Participants and the Plan Administrator
of Pioneer Natural Resources USA, Inc. 401(k) and Matching Plan:


We have audited the accompanying statements of net assets available for benefits
of Pioneer  Natural  Resources USA, Inc. 401(k) and Matching Plan as of December
31, 2003 and 2002, and the related  statement of changes in net assets available
for benefits for the year ended December 31, 2003.  These  financial  statements
are the  responsibility  of the  Plan's  management.  Our  responsibility  is to
express an opinion on these financial statements based on our audits.

We conducted our audits in accordance  with the standards of the Public  Company
Accounting Oversight Board (United States). Those standards require that we plan
and perform the audit to obtain reasonable assurance about whether the financial
statements are free of material misstatement.  An audit includes examining, on a
test basis,  evidence  supporting  the amounts and  disclosures in the financial
statements.  An audit also includes assessing the accounting principles used and
significant  estimates  made by  management,  as well as evaluating  the overall
financial  statement  presentation.   We  believe  that  our  audits  provide  a
reasonable basis for our opinion.

In our opinion,  the financial  statements  referred to above present fairly, in
all  material  respects,  the net assets  available  for benefits of the Plan at
December  31,  2003 and 2002,  and the changes in its net assets  available  for
benefits for the year ended December 31, 2003, in conformity with U.S. generally
accepted accounting principles.

Our audits were performed for the purpose of forming an opinion on the financial
statements taken as a whole. The  accompanying  supplemental  schedule of assets
(held at end of year) as of December 31, 2003,  is presented  for the purpose of
additional  analysis and is not a required part of the financial  statements but
is  supplementary  information  required by the  Department of Labor's Rules and
Regulations for Reporting and Disclosure  under the Employee  Retirement  Income
Security Act of 1974. This  supplemental  schedule is the  responsibility of the
Plan's management.  The supplemental schedule has been subjected to the auditing
procedures  applied  in our  audits  of the  financial  statements  and,  in our
opinion,  is fairly stated in all material respects in relation to the financial
statements taken as a whole.



                                      Ernst & Young LLP




Fort Worth, Texas
June 7, 2004


                                       4










          PIONEER NATURAL RESOURCES USA, INC. 401(k) AND MATCHING PLAN


                 Statements of Net Assets Available for Benefits




                                                                    December 31,
                                                          -------------------------------
                                                              2003               2002
                                                          ------------       ------------
                                                                       
Investments at fair value:
  Vanguard PRIMECAP Fund...............................   $ 27,137,082       $ 18,022,434
  Vanguard Prime Money Market Fund.....................     12,564,723         15,269,243
  Vanguard 500 Index Fund..............................     15,278,207         10,677,404
  Vanguard Windsor II Fund.............................     12,748,739          9,007,662
  Vanguard Short-Term Corporate Fund...................      4,976,563          5,235,030
  Vanguard Total Bond Market Index Fund................      2,853,005          2,937,616
  Vanguard International Growth Fund...................      2,081,153          1,308,748
  Vanguard Asset Allocation Fund.......................      2,244,572          1,189,465
  Vanguard Explorer Fund...............................      3,325,419            730,228
  Vanguard Retirement Savings Trust....................      2,598,710                -
  Vanguard Inflation-Protected Securities Fund.........        942,171                -
  Sarofim Equity Fund..................................     14,842,386         13,136,875
  Pioneer Stock Investment Fund .......................      4,964,217          4,768,989
                                                           -----------        -----------
                                                           106,556,947         82,283,694
Participants loans receivable..........................      2,150,262          1,531,468
                                                           -----------        -----------
                                                           108,707,209         83,815,162
Contributions receivable...............................         25,328                -
Unallocated administrative expenses....................            -               (9,869)
                                                           -----------        -----------
  Net assets available for benefits....................   $108,732,537       $ 83,805,293
                                                           ===========        ===========




                 See accompanying notes to financial statements.


                                        5








          PIONEER NATURAL RESOURCES USA, INC. 401(k) AND MATCHING PLAN


            Statement of Changes in Net Assets Available for Benefits
                      For the Year Ended December 31, 2003




                                                            
Additions to net assets available for benefits:
  Interest and dividend income.............................    $  1,294,681
  Employer contributions...................................       5,120,543
  Participants contributions...............................       4,075,674
  Net appreciation in fair value of investments............      17,812,101
  Rollovers................................................         399,963
                                                                -----------
                                                                 28,702,962
                                                                -----------
Deductions from net assets available for benefits:
  Distributions to participants............................       3,761,411
  Administrative expenses..................................          14,307
                                                                -----------
                                                                  3,775,718
                                                                -----------

Net increase in net assets available for benefits..........      24,927,244

Net assets available for benefits, beginning of year.......      83,805,293
                                                                -----------
Net assets available for benefits, end of year.............    $108,732,537
                                                                ===========



                 See accompanying notes to financial statements.


                                       6







          PIONEER NATURAL RESOURCES USA, INC. 401(k) AND MATCHING PLAN

                          NOTES TO FINANCIAL STATEMENTS
                           December 31, 2003 and 2002


Note 1.     Description of Plan

     The following description of the Pioneer Natural Resources USA, Inc. 401(k)
and Matching Plan (the "Plan") provides only general  information.  Participants
should refer to the Summary Plan  Description for a complete  description of the
Plan, a copy of which is available to each  participant from the Pioneer Natural
Resources   USA,   Inc.   401(k)  and  Matching   Plan   Committee   (the  "Plan
Administrator").  The  Plan  is  subject  to  the  provisions  of  the  Employee
Retirement Income Security Act of 1974, as amended ("ERISA").

     General

     The Plan is a defined  contribution  plan  established  on  January 1, 1990
under Section 401 of the Internal Revenue Code of 1986, as amended (the "Code").
The Plan was  established  for the benefit of the  employees of Pioneer  Natural
Resources  USA,  Inc. (the  "Employer"),  a  wholly-owned  subsidiary of Pioneer
Natural Resources  Company (the "Company").  All regular full-time and part-time
employees of the Employer are eligible to  participate  in the Plan on the first
day of the month  following  their date of hire. The Plan's assets are held in a
trust and certain  administrative  functions are performed by Vanguard Fiduciary
Trust Company, the trustee of the trust (the "Trustee").

     Contributions

     Participants may elect to contribute to the Plan an amount of not less than
two percent nor more than 30 percent of their  pre-tax  annual salary and bonus.
Additionally,  participants  may elect to make  after-tax  contributions  to the
Plan. A participant's  combined pre-tax and after-tax  contributions to the Plan
(the "Participant Contributions") may not exceed 50 percent of the participant's
annual salary and bonus. Matching  contributions are made in cash to the Plan at
an amount  equal to 200  percent  of the first five  percent  of pre-tax  annual
salary contributed by a participant to the Plan (the "Matching Contributions").

     Participants Accounts

     Participant's accounts are credited with the Participant Contributions, the
Matching  Contributions  and an allocation  of Plan earnings and  administrative
expenses.  Plan  earnings  and  administrative  expenses  are  allocated to each
participant's  accounts by fund in proportion to their fund balance  relative to
the total fund balance.

     Participants  may borrow  from  their  accounts a minimum of $1,000 up to a
maximum of $50,000 or 50 percent of their accounts' vested  balances,  whichever
amount is less.  The loans  are  secured  by the  balance  in the  participant's
accounts.  Participants loans bear interest at an annual rate equal to the prime
borrowing rate at the inception of the loan plus one percent. Loan principal and
interest is paid ratably through payroll deductions.

     Investment Options

     During the Plan year ended  December  31, 2003,  participants  were able to
allocate their contributions among the following  registered  investment company
funds,  common/collective trusts and Pioneer Stock Investment Fund (the "Pioneer
Stock Fund"):

     Registered Investment Company Funds:

     o    Vanguard PRIMECAP Fund  -  Invests in  stocks of companies with above-
          average  prospects for  continued  earnings  growth,  strong  industry
          positions and skilled management teams.


                                       7






          PIONEER NATURAL RESOURCES USA, INC. 401(k) AND MATCHING PLAN

                          NOTES TO FINANCIAL STATEMENTS
                           December 31, 2003 and 2002



Note 1.     Description of Plan (continued)

     o    Vanguard Prime Money Market Fund - Invests in high-quality, short-term
          money  market  instruments  issued  by  financial  institutions,  non-
          financial corporations, the United States government and United States
          federal agencies.

     o    Vanguard 500 Index Fund - Invests  in all  of the 500 stocks that make
          up the  Standard & Poor's  500 Composite  Stock Price Index,  a widely
          recognized benchmark of United States stock market performance.

     o    Vanguard Windsor II Fund - Invests  in a  diversified  group of large-
          capitalization  companies whose  stocks are  considered  by the fund's
          advisors to be undervalued or out-of-favor.  The stocks generally sell
          at prices considered by the  fund's advisors to be below their overall
          market average  compared to  their dividend income  and future  return
          potential.

     o    Vanguard  Short-Term  Corporate  Fund - Invests in  short-term  bonds,
          including  investment-grade  corporate  and   United  States  Treasury
          securities.

     o    Vanguard Total Bond Market Index Fund - Invests  in a  large sample of
          securities  that  match  key characteristics  of the  Lehman  Brothers
          Aggregate Bond Index.

     o    Vanguard  International  Growth Fund - Invests  in stocks  of seasoned
          companies located outside the United States  with above-average growth
          potential.

     o    Vanguard Asset Allocation Fund - Invests in  common stocks,  long-term
          United States Treasury bonds and money market instruments.

     o    Vanguard  Explorer  Fund - Invests  in a  diversified  group of small-
          company stocks with prospects for above-average growth.

     o    Vanguard Inflation-Protected  Securities Fund - Invests in  inflation-
          indexed bonds issued by the United States government, its agencies and
          instrumentalities, and corporations.

     Common/Collective Trusts:

     o    Vanguard Retirement Savings  Trust - Invests  in  high-quality  fixed-
          income securities with  financial backing from insurance companies and
          banks.

     o    Sarofim Equity Fund - Invests  in a  diversified group of large, high-
          quality, multinational  companies with favorable  growth prospects and
          high incremental returns on investment.

     Pioneer Stock Fund - The  Pioneer  Stock Fund  is designed to provide long-
     term growth of capital  through increases  in the value of the common stock
     of the Company. Dividends are reinvested to purchase more shares.

     See Note 3  for  additional  information  regarding  investment  risks  and
     uncertainties.


                                       8










          PIONEER NATURAL RESOURCES USA, INC. 401(k) AND MATCHING PLAN

                          NOTES TO FINANCIAL STATEMENTS
                           December 31, 2003 and 2002


Note 1.     Description of Plan (continued)

     Vesting

     Participants are immediately vested in their Participant Contributions made
into the Plan, plus the actual Plan earnings  thereon.  Participants vest in the
Matching Contributions,  plus the actual Plan earnings thereon,  proportionately
over a  four-year  period  that  begins  with  the  Participant's  date of hire.
Participant's  account  balances that were merged into the Plan from predecessor
plans  retain the  vesting  schedules  provided  for in the  predecessor  plans'
documents.

     Payments of Benefits

     Vested  balances > $5,000.  If the total value of the vested portion of the
participant's  account exceeds $5,000,  payments will begin at age 70-1/2 unless
the participant terminates,  retires or becomes disabled prior to age 70-1/2 and
consents to an earlier distribution date by filing a written request to the Plan
Administrator.  Distributions  to terminated,  retired or disabled  participants
will be annuities,  but may be installments or lump-sum  payments if so directed
by the participant.

     Vested  balances < $5,000.  If the total value of the vested portion of the
participant's  accounts is $5,000 or less,  payment will be made in one lump sum
as soon as administratively possible.

     In either case,  vested amounts that are invested in the Pioneer Stock Fund
may,  at the  election of the  participant,  be  distributed  in the form of the
Company's  common stock with cash  distributed  in lieu of fractional  shares of
stock.   Under  the  Plan,  a   participant's   beneficiary   will  receive  the
participant's account balances in the event of a participant's death.

     Withdrawal of Benefits

     Current  employees  of the  Employer  may  withdraw (i) all or a portion of
their account  balances  derived from after- tax  Participant  Contributions  or
rollover  contributions;  (ii) their  vested  assets in the Plan  under  certain
hardship  conditions  as  defined  in  the  Plan  agreement;  or  (iii),  if the
participant  has attained the age of 59-1/2,  all or a portion of their  account
balances  derived from  Participant  Contributions  and Plan  earnings  thereon.
Terminated participants may withdraw their vested assets in the Plan.

     Forfeitures

     Upon  termination of employment,  the unvested  portion of a  participant's
Matching Contributions is forfeited to the Plan. Forfeitures are used to pay for
administrative  expenses  incurred  by the  Plan or used on an  annual  basis to
reduce  the  total  amount  of  Matching  Contributions  made to the Plan by the
Employer.

     Plan Termination

     Although it has not  expressed  any intent to do so, the  Employer  has the
right under the Plan,  subject to the provisions of ERISA,  to  discontinue  its
contributions  at any time or to terminate  the Plan. In the event of the Plan's
termination  or the complete  discontinuance  of Matching  Contributions  to the
Plan, participants will immediately become fully vested in their accounts.


                                       9








          PIONEER NATURAL RESOURCES USA, INC. 401(k) AND MATCHING PLAN

                          NOTES TO FINANCIAL STATEMENTS
                           December 31, 2003 and 2002


Note 2.     Summary of Significant Accounting Policies

     Basis of Presentation

     The accompanying  financial statements have been prepared under the accrual
basis  of  accounting  in  accordance  with  United  States  generally  accepted
accounting principles ("GAAP").

     Benefit payments made to participants are recorded when paid.

     Investment Valuation

     The Plan's  investments  are stated at fair value in the  Statements of Net
Assets Available for Benefits as of December 31, 2003 and 2002, as determined by
the Trustee. Investment fair values are determined as follows:

     1.  Investments in  registered  investment  company funds  are valued using
         published market prices which  represent the net  asset value of shares
         or units held by the Plan as of December 31.

     2.  Investments in common/collective trusts  are valued based upon the fair
         values of the underlying net assets of the trusts, as determined by the
         Trustee.

     3.  Investments  in the  Company's  common  stock  are  valued at  the last
         reported sales price on December 31.

     4.  Participants loans  receivable  are valued  at their  unpaid  principal
         balance, which approximates fair value.

     Security Transactions and Investment Income

     Security  transactions  are accounted for on a trade-date  basis.  Expenses
incurred with transactions,  if any, are added to the purchase price or deducted
from the  selling  price at the time of the  transactions.  Dividend  income  is
recorded on the  ex-dividend  date.  Interest income is recorded as earned on an
accrual basis.

     Use of Estimates

     The preparation of the accompanying  financial statements and related notes
in conformity  with GAAP requires the Plan's  management to make  estimates that
affect  the  reported  amounts  of  assets  and  liabilities  at the date of the
financial  statements  and the reported  amounts of additions to and  deductions
from net assets  available  for benefits  during the  reporting  period.  Actual
results could differ from those estimates.


                                       10








          PIONEER NATURAL RESOURCES USA, INC. 401(k) AND MATCHING PLAN

                          NOTES TO FINANCIAL STATEMENTS
                           December 31, 2003 and 2002


Note 3.     Investments

     The  Trustee  holds the Plan's  investments  and  executes  all  investment
transactions.

     During  2003,  the  fair  value  of  the  Plan's   investments   (including
investments purchased, sold and held during the year) appreciated as follows:

                                                                  
     Net realized gains:
        Registered investment company funds.......................   $   588,526
        Common/collective trusts..................................       157,797
        Pioneer Stock Fund........................................       169,452
                                                                      ----------
            Total net realized gains..............................       915,775
                                                                      ----------
     Net unrealized gains:
        Registered investment company funds.......................    13,334,330
        Common/collective trusts..................................     2,547,664
        Pioneer Stock Fund........................................     1,014,332
                                                                      ----------
            Total net unrealized gains............................    16,896,326
                                                                      ----------
            Net appreciation in fair value of investments.........   $17,812,101
                                                                      ==========


     The fair values of the Plan's  investments are subject to a number of risks
and uncertainties.  These risks and uncertainties  include,  among other things,
interest rate risk,  credit risk,  political  risk,  general  business risks and
overall  market  volatility  risk.  As  described in Note 1,  participants  have
investment  options to which they may allocate their  contributions  and account
balances. Those investment options have individual risk profiles that cause them
to  respond  differently  to changes  in the risks and  uncertainties  described
above.  Due to the level of risk associated with the Plan's  investments,  it is
reasonably  possible that changes in the fair values of the Plan investments may
occur during the future, and that such changes could cause the Plan's net assets
available for benefits to differ  materially  from those reported as of December
31, 2003.

Note 4.     Administrative Expenses

     Administrative  expenses  incurred by the Plan were $14,307 during the year
ended December 31, 2003. The Employer may pay certain  expenses  incurred in the
establishment and administration of the Plan, including expenses and fees of the
Trustee,  but is not  obligated  to do so.  Any  Plan  expenses  not paid by the
Employer  are  paid  from  the  Plan's  earnings  or  from  qualifying   account
forfeitures.  In  addition to  administrative  expenses  paid by the Plan,  Plan
administrative  expenses of $21,104  were paid by the  Employer  during 2003 and
administrative  expenses of $10,111  related to 2003  activity  were paid by the
Employer  subsequent to December 31, 2003.  Account  forfeiture  balances in the
Plan qualifying to be used to defray Plan administrative expenses totaled $7,849
as of December 31, 2003.

Note 5.     Tax Status of the Plan

     The Plan received a determination  letter from the Internal Revenue Service
dated March 19, 2003,  stating that the Plan is qualified  under Sections 401(a)
and  501(a)  of the Code  and,  therefore,  the  related  trust is  exempt  from
taxation.  The  Plan is  required  to  operate  in  conformity  with the Code to
maintain its qualification.  The Plan  Administrator  believes the Plan is being
operated  in  compliance  with the  applicable  requirements  of the  Code  and,
therefore,  believes  that the Plan is  qualified  and the related  trust is tax
exempt.


                                       11








          PIONEER NATURAL RESOURCES USA, INC. 401(k) AND MATCHING PLAN

                          NOTES TO FINANCIAL STATEMENTS
                           December 31, 2003 and 2002


Note 6.     Related Party Transactions

     Certain Plan  investments  are in shares or units of registered  investment
company funds and a common/collective  trust that are managed by the Trustee and
the Pioneer Stock Fund. Plan transactions in registered investment company funds
and a  common/collective  trust that are  managed by the Trustee and the Pioneer
Stock Fund qualify as party-in- interest transactions.

Note 7.     Reconciliation of Financial Statements to Form 5500

     The following is a reconciliation  of net assets available for benefits per
the financial statements to Form 5500 as of December 31, 2003:

                                                                
  Net assets available for benefits per the accompanying
      financial statements.......................................  $108,732,537
  Amounts due to withdrawing participants........................      (139,599)
                                                                    -----------

      Net assets available for benefits per Form 5500............  $108,592,938
                                                                    ===========


     The following is a reconciliation  of distributions to participants  during
the year ended December 31, 2003, per the financial statements to Form 5500:

                                                                
  Distributions to participants per the accompanying
      financial statements.......................................  $  3,761,411
  Amounts due to withdrawing participants at December 31, 2003...       139,599
                                                                    -----------
      Distributions to participants per Form 5500................  $  3,901,010
                                                                    ===========


     Amounts  due to  withdrawing  participants  are  recorded  on Form 5500 for
distributions to participants  that have been processed and approved for payment
prior to December 31, but remained unpaid as of that date.


                                       12













          PIONEER NATURAL RESOURCES USA, INC. 401(k) AND MATCHING PLAN


         Schedule H; Line 4i - Schedule of Assets (Held At End of Year)
                                 EIN: 75-2516853
                                Plan Number: 001

                             As of December 31, 2003


                                                            (c)
                                                       Description of
                      (b)                           investment including
              Identity of issuer,                  maturity date, rate of                 (e)
               borrower, lessor,                  interest, collateral, par             Current
(a)            or similar party                       or maturity value                  Value
---    --------------------------------    ---------------------------------------    ------------
                                                                             
 *     Vanguard Fiduciary Trust Company    Vanguard PRIMECAP Fund -
                                               511,634 shares                         $ 27,137,082
 *     Vanguard Fiduciary Trust Company    Vanguard Prime Money Market Fund -
                                               12,564,723 shares                        12,564,723
 *     Vanguard Fiduciary Trust Company    Vanguard 500 Index Fund -
                                               148,809 shares                           15,278,207
 *     Vanguard Fiduciary Trust Company    Vanguard Windsor II Fund -
                                               481,266 shares                           12,748,739
 *     Vanguard Fiduciary Trust Company    Vanguard Short-Term Corporate Fund -
                                               460,793 shares                            4,976,563
 *     Vanguard Fiduciary Trust Company    Vanguard Total Bond Market Index Fund -
                                               276,722 shares                            2,853,005
 *     Vanguard Fiduciary Trust Company    Vanguard International Growth Fund -
                                               129,024 shares                            2,081,153
 *     Vanguard Fiduciary Trust Company    Vanguard Asset Allocation Fund -
                                               99,493 shares                             2,244,572
 *     Vanguard Fiduciary Trust Company    Vanguard Explorer Fund -
                                               50,677 shares                             3,325,419
 *     Vanguard Fiduciary Trust Company    Vanguard Retirement Savings Trust -
                                               2,598,710 shares                          2,598,710
 *     Vanguard Fiduciary Trust Company    Vanguard Inflation-Protected Securities
                                               Fund - 77,164 shares                        942,171
       Fayez Sarofim & Co.                 Sarofim Equity Fund -
                                               307,614 shares                           14,842,386
 *     Pioneer Natural Resources Company   Pioneer Stock Investment Fund -
                                               432,423 units                             4,964,217
 *     Participants loans receivable       Interest rates range from 5.0% to 10.5%       2,150,262
                                                                                       -----------
                                                                                      $108,707,209
                                                                                       ===========

--------------------------
*Party-in-interest

Note: Column (d) is not applicable since all investments are participant directed.




                                       13











          PIONEER NATURAL RESOURCES USA, INC. 401(k) AND MATCHING PLAN

                               S I G N A T U R E S


Pursuant to the  requirements  of the Securities  Exchange Act of 1934, the Plan
Administrator  has duly caused this annual  report to be signed on its behalf by
the undersigned hereunto duly authorized.

                            PIONEER NATURAL RESOURCES USA, INC.
                            401(k) AND MATCHING PLAN


Date:  June 25, 2004      By:    /s/ Larry N. Paulsen
                                -----------------------------------------------
                                Larry N. Paulsen
                                Chairman of Pioneer Natural Resources USA, Inc.
                                401(k) and Matching Plan Committee


Date:  June 25, 2004      By:    /s/ Richard P. Dealy
                                -----------------------------------------------
                                Richard P. Dealy
                                Member of Pioneer Natural Resources USA, Inc.
                                401(k) and Matching Plan Committee


Date:  June 25, 2004      By:    /s/ Kerry D. Scott
                                -----------------------------------------------
                                Kerry D. Scott
                                Member of Pioneer Natural Resources USA, Inc.
                                401(k) and Matching Plan Committee


Date:  June 25, 2004      By:    /s/ Kevin Schepel
                                -----------------------------------------------
                                Kevin Schepel
                                Member of Pioneer Natural Resources USA, Inc.
                                401(k) and Matching Plan Committee


Date:  June 25, 2004      By:    /s/ David W. Simpson
                                -----------------------------------------------
                                David W. Simpson
                                Member of Pioneer Natural Resources USA, Inc.
                                401(k) and Matching Plan Committee


Date:  June 25, 2004      By:    /s/ Susan A. Spratlen
                                -----------------------------------------------
                                Susan A. Spratlen
                                Member of Pioneer Natural Resources USA, Inc.
                                401(k) and Matching Plan Committee


                                       14











          PIONEER NATURAL RESOURCES USA, INC. 401(k) AND MATCHING PLAN

                                INDEX TO EXHIBITS



Exhibit
Number                          Description                               Page
-------                         -----------                               ----

23.1 (a)    Consent of Independent Registered Public Accounting Firm       16



--------------
(a)   Filed herewith



                                       15