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

                                  SCHEDULE 13G

                    Under the Securities Exchange Act of 1934

                               (Amendment No. 10)*

                              KILROY REALTY CORP.
                      ----------------------------------------
                                (Name of Issuer)

                                    COMMON
                               --------------------
                         (Title of Class of Securities)

                                    49427F108
                                  --------------
                                 (CUSIP Number)


             Date of Event which Requires Filing of this Statement

                                December 31, 2006
                               --------------------

Check the appropriate box to designate the rule pursuant to which the Schedule
is filed:

[x]     Rule 13d-1(b)
[ ]     Rule 13d-1(c)
[ ]     Rule 13d-1(d)

* The remainder of this cover page shall be filled out for a reporting  person's
initial filing on this form with respect to the subject class of securities, and
for any  subsequent  amendment  containing  information  which  would  alter the
disclosures provided in prior coverage.

The information required in the remainder of this cover page shall not be deemed
to be "filed" for the purpose of the Securities  Exchange Act of 1934 ("Act") or
otherwise  subject to the  liabilities  of that  section of the Act but shall be
subject to all other provisions of the Act (however, see the Notes).

SEC 1745 (12-02)


                                   Page 1




                                               Page 2 of 7 Pages

Amendment No. 10 to Schedule 13G (continued)

CUSIP No. 49427F108
- -----------------------------------------------------------------------------
   1   NAME OF REPORTING PERSON
       S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

       Cohen & Steers, Inc. 14-1904657
- -----------------------------------------------------------------------------
   2   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                             (a)  [ ]
                                                             (b)  [x]
- -----------------------------------------------------------------------------
   3   SEC USE ONLY


- -----------------------------------------------------------------------------
   4   CITIZENSHIP OR PLACE OF ORGANIZATION

       New York
- -----------------------------------------------------------------------------
   NUMBER OF      5    SOLE VOTING POWER
     SHARES            2,473,808
  BENEFICIALLY    -------------------------------------------------------------
    OWNED BY      6    SHARED VOTING POWER
      EACH             40,675
   REPORTING      -------------------------------------------------------------
     PERSON       7    SOLE DISPOSITIVE POWER
      WITH             2,848,708
                  -------------------------------------------------------------
                  8    SHARED DISPOSITIVE POWER
                       40,675
-------------------------------------------------------------------------------
   9   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

       2,889,383
-------------------------------------------------------------------------------
  10   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*


-------------------------------------------------------------------------------
  11   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

       8.9%
-------------------------------------------------------------------------------
  12   TYPE OF REPORTING PERSON*

       HC, CO
-------------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT




                                                Page 3 of 7 Pages


Amendment No. 10 to Schedule 13G (continued)

CUSIP No. 49427F108
- -----------------------------------------------------------------------------
   1   NAME OF REPORTING PERSON
       S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

       Cohen & Steers Capital Management, Inc.     13-3353336
- -----------------------------------------------------------------------------
   2   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                             (a)  [ ]
                                                             (b)  [x]
- -----------------------------------------------------------------------------
   3   SEC USE ONLY


- -----------------------------------------------------------------------------
   4   CITIZENSHIP OR PLACE OF ORGANIZATION

       New York
- -----------------------------------------------------------------------------
   NUMBER OF      5    SOLE VOTING POWER
     SHARES            2,473,808
  BENEFICIALLY    -------------------------------------------------------------
    OWNED BY      6    SHARED VOTING POWER
      EACH             0
   REPORTING      -------------------------------------------------------------
     PERSON       7    SOLE DISPOSITIVE POWER
      WITH             2,848,708
                  -------------------------------------------------------------
                  8    SHARED DISPOSITIVE POWER
                       0
- -----------------------------------------------------------------------------
   9   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

       2,848,708
- -----------------------------------------------------------------------------
  10   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

- -----------------------------------------------------------------------------
  11   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

       8.8%
- -----------------------------------------------------------------------------
  12   TYPE OF REPORTING PERSON*

       IA, CO
- -----------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT




                                                Page 4 of 7 Pages

Amendment No. 10 to Schedule 13G (continued)

CUSIP No.  49427F108
-------------------------------------------------------------------------------
1)  NAME OF REPORTING PERSON
    S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON (entities only)

    Houlihan Rovers SA
-------------------------------------------------------------------------------
2)  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                          (a) [ ]
                                                          (b) [x]
-------------------------------------------------------------------------------
3)  SEC USE ONLY


-------------------------------------------------------------------------------
4)  CITIZENSHIP OR PLACE OF ORGANIZATION

    Belgium
-------------------------------------------------------------------------------
    NUMBER        5)   SOLE VOTING POWER
    OF                 40,675
    SHARES        -------------------------------------------------------------
    BENEFICIALLY  6)   SHARED VOTING POWER
    OWNED BY           0
    EACH          -------------------------------------------------------------
    REPORTING     7)   SOLE DISPOSITIVE POWER
    PERSON             40,675
    WITH          -------------------------------------------------------------
                  8)   SHARED DISPOSITIVE POWER
                       0
-------------------------------------------------------------------------------
9)  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

    40,675
-------------------------------------------------------------------------------
10) CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES [ ]

-------------------------------------------------------------------------------
11) PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

    0.1%
-------------------------------------------------------------------------------
12) TYPE OF REPORTING PERSON

    IA
-------------------------------------------------------------------------------

                     *SEE INSTRUCTIONS BEFORE FILLING OUT!





                                                Page 5 of 7 Pages

Amendment No. 10 to Schedule 13G (continued)


Item 1.

        (a)  Name of Issuer:
               KILROY REALTY CORP

        (b)  Address of Issuer's Principal Executive Offices:
               2250 E Imperial Hwy
               C/O Kilroy Industries
               El Segundo, CA 90245

Item 2.

        (a)  Name of Persons Filing:
               Cohen & Steers, Inc.
               Cohen & Steers Capital Management, Inc.
               Houlihan Rovers SA
        (b)  Address of Principal Business Office:
               The principal address for Cohen & Steers Capital Management,
               Inc. is:
               280 Park Avenue
               10th Floor
               New York, NY 10017

               The principal address for Houlihan Rovers SA is:
               Chausee de la Hulpe 116,
               1170 Brussels, Belgium
        (c)  Citizenship:
               Cohen & Steers, Inc: Delaware Corporations
               Cohen & Steers Capital Management, Inc: New York Corporation
               Houlihan Rovers SA: Belgium
        (d)  Title of Class Securities:
               Commmon
        (e)  CUSIP Number:
               49427F108


Item 3.     If this statement is filed pursuant to Rule 13d-l(b), or
            13d-2(b), check whether the person filing is a

            (a)  [ ]  Broker or Dealer registered under Section 15 of the Act

            (b)  [ ]  Bank as defined in Section 3(a)(6) of the Act

            (c)  [ ]  Insurance Company as defined in section 3(a)(19) of
                      the Act

            (d)  [ ]  Investment Company registered under Section 8 of the
                      Investment Company Act

            (e)  [x]  An investment advisor in accordance with Section
                      240.13d-1(b)(1)(ii)(E)

            (f)  [ ]  An employee benefit plan or endowment fund in accordance
                      with 240.13d-1(b)(1)(ii)(F)

            (g)  [x]  A parent holding company or control person in accordance
                      with Section 240.13d-l(b)(1)(ii)(G)

            (h)  [ ]  A savings association as defined in Section 3(b) of the
                      Federal Deposit Insurance Act (12 U.S.C. 1813)

            (i)  [ ]  A church plan that is excluded from the definition of an
                      investment company under section 3(c)(14) of the
                      Investment Company Act of 1940 (15U.S.C. 80a-3)

            (j)  [ ]  Group, in accordance with Section 240.13d-1(b)(l)(ii)(J)



                                                 Page 6 of 7 Pages


Item 4.  OWNERSHIP:

         (a) Amount Beneficially Owned as of December 31, 2006:

               See row 9 on cover sheet

         (b) Percent of Class:

               See row 11 on cover sheet


          (c) Number of shares as to which such person has:
                (i)   sole power to vote or direct the vote:
                         See row 5 on cover sheet

                (ii)  shared power to vote or direct the vote:
                         See row 6 on cover sheet

                (iii) sole power to dispose or to direct
                      the disposition of:
                          See row 7 on cover sheet

                (iv)  shared power to dispose or direct
                      the disposition of:
                          See row 8 on cover sheet


Item 5.  OWNERSHIP  OF 5% OR LESS OF A CLASS
         N/A

Item 6.  OWNERSHIP OF MORE THAN 5% ON BEHALF OF ANOTHER PERSON
         N/A

Item 7.  IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH
         ACQUIRED THE SECURITY BEING REPORTED ON BY THE PARENT
         HOLDING COMPANY

         Cohen & Steers, Inc holds a 100% interest in Cohen & Steers Capital
         Management, Inc., and investment advisor registered under Section 203
         of the Investment Advisers Act, and holds a 50% interest in Houlihan
         Rover SA, an investment advisor registered under Section 203 of the
         Investment Advisers Act.

Item 8.  IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE GROUP

         Cohen & Steers, Inc holds a 100% interest in Cohen & Steers Capital
         Management, Inc., and investment advisor registerd under Section 203
         of the Investment Advisers Act, and holds a 50% interest in Houlihan
         Rover SA, an investment advisor registered under Section 203 of the
         Investment Advisers Act.





                                                 Page  6 of 7 Pages

Item 9.  NOTICE OF DISSOLUTION OF GROUP

         N/A

Item 10. Certification

     By signing  below I certify  that,  to the best of my knowledge and belief,
the  securities  referred  to above  were  acquired  in the  ordinary  course of
business  and were not acquired for the purpose of and do not have the effect of
changing or  influencing  the control of the issuer of such  securities and were
not acquired in connection  with or as a participant in any  transaction  having
such purposes or effect.

Signature

After  reasonable  inquiry and to the best of my knowledge and belief, I certify
that the information set forth in this statement is true, complete and correct.

Date:  February 13, 2007

                        Cohen & Steers, Inc.
                        Cohen & Steers Capital Management, Inc.
                        By:

                        /s/ Robert Steers
                        --------------------------------------------
                            Signature


                            Robert H. Steers, Co-Chairman and Co-CEO
                            Cohen & Steers Inc.
                            Cohen & Steers Capital Management, Inc.
                        --------------------------------------------
                            Name and Title


                        Houlihan Rovers SA
                        By:

                        /s/ Joseph Houlihan
                        --------------------------------------------
                            Signature

                            Joseph Houlihan, Managing Director
                            Houlihan Rovers SA
                        --------------------------------------------
                            Name and Title





                                             Page 7 of 7 Pages



                             JOINT FILING AGREEMENT

     In accordance with Rule 13d-1(k)  promulgated under the Securities Exchange
Act of 1934, as amended,  the undersigned  hereby agree to the joint filing with
all  other  Reporting  Persons  (as such term is  defined  in the  Schedule  13G
referred  to below) on behalf of each of them of a  Statement  on  Schedule  13G
including amendments thereto) with respect to the Common Shares of KILROY REALTY
CORP.  and that this  Agreement  may be  included  as an  Exhibit  to such joint
filing.  This  Agreement may be executed in any number of  counterparts,  all of
which together shall constitute one and the same instrument.

     IN WITNESS  WHEREOF,  the  undersigned  hereby execute this Agreement as of
February 13, 2007.

            Cohen & Steers, Inc.
                        Cohen & Steers Capital Management, Inc.
                        By:

                        /s/ Robert Steers
                        ----------------------------------------------
                            Signature


                            Robert H. Steers, Co-Chairman and Co-CEO
                            Cohen & Steers Inc.
                            Cohen & Steers Capital Management, Inc.
                         ---------------------------------------------
                            Name and Title


                        Houlihan Rovers SA
                        By:

                        /s/ Joseph Houlihan
                        ---------------------------------------------
                            Signature

                            Joseph Houlihan, Managing Director
                            Houlihan Rovers SA
                        ---------------------------------------------
                            Name and Title