Ownership Submission
FORM 5
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
Form 3 Holdings Reported
Form 4 Transactions Reported
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

ANNUAL STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
OMB APPROVAL
OMB Number: 3235-0362
Expires: January 31, 2005
Estimated average burden hours per response... 1.0

1. Name and Address of Reporting Person *
ACKLEY ROBERT W
2. Issuer Name and Ticker or Trading Symbol
CROMPTON CORP [CK]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
Executive V.P. - Polymer Proc.
(Last)
(First)
(Middle)

CROMPTON CORPORATION, 1 EXTRUSION DRIVE
3. Statement for Issuer's Fiscal Year Ended (Month/Day/Year)
12/31/2004
(Street)


PAWCATUCK, CT 06379
4. If Amendment, Date Original Filed(Month/Day/Year)
6. Individual or Joint/Group Reporting
(check applicable line)

_X_ Form Filed by One Reporting Person
___ Form Filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)
2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)
4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)
5. Amount of Securities Beneficially Owned at end of Issuer's Fiscal Year
(Instr. 3 and 4)
6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)
7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Amount (A) or (D) Price
Common Stock             163,643 D  
Common Stock             2,601.4596 I By Wife
Common Stock             3,357.6896 I ESOP Trust
Common Stock             35,870.77 I LTIP Trust (1TA)
Common Stock             15,037.14 I LTIP Trust 1988
Common Stock             49.8341 I ESPP
Common Stock             25,689 I Restricted Stock Account

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly. Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number. SEC 2270 (9-02)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)
2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)
5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)
6. Date Exercisable and Expiration Date
(Month/Day/Year)
7. Title and Amount of Underlying Securities
(Instr. 3 and 4)
8. Price of Derivative Security
(Instr. 5)
9. Number of Derivative Securities Beneficially Owned at End of Issuer's Fiscal Year
(Instr. 4)
10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)
11. Nature of Indirect Beneficial Ownership
(Instr. 4)
(A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
NQ Stock Option (Right to Buy) $ 5.85           10/20/2004 11/19/2013 Common Stock
45,000
  45,000
D
 
NQ Stock Option (Right to Buy) $ 6.38           01/21/2004 02/20/2013 Common Stock
43,654
  43,654
D
 
NQ Stock Option (Right to Buy) $ 7.25           10/22/2003 11/21/2012 Common Stock
26,207
  26,207
D
 
NQ Stock Option (Right to Buy) $ 7.92           10/23/2002 11/22/2011 Common Stock
47,374
  47,374
D
 
NQ Stock Option (Right to Buy) $ 8.1562           10/31/2001 11/30/2010 Common Stock
75,000
  75,000
D
 
NQ Stock Option (Right to Buy) $ 8.3437           10/19/2000 11/19/2009 Common Stock
88,015
  88,015
D
 
NQ Stock Option (Right to Buy) $ 13           08/04/1999 12/18/2005 Common Stock
18,808
  18,808
D
 
NQ Stock Option (Right to Buy) $ 14.3438           08/05/1999 11/14/2008 Common Stock
50,000
  50,000
D
 
NQ Stock Option (Right to Buy) $ 14.5           08/04/1999 09/21/2006 Common Stock
72,416
  72,416
D
 
NQ Stock Option (Right to Buy) $ 16.875           08/04/1999 11/16/2006 Common Stock
20,000
  20,000
D
 
NQ Stock Option (Right to Buy) $ 26.4063           08/04/1999 11/07/2007 Common Stock
20,000
  20,000
D
 
ISO Stock Option (Right to Buy) $ 6.38           01/21/2005 01/21/2013 Common Stock
31,346
  31,346
D
 
ISO Stock Option (Right to Buy) $ 7.25           10/22/2004 10/22/2012 Common Stock
13,793
  13,793
D
 
ISO Stock Option (Right to Buy) $ 7.92           10/23/2003 10/23/2011 Common Stock
12,626
  12,626
D
 
ISO Stock Option (Right to Buy) $ 8.3437           10/19/2002 10/19/2009 Common Stock
11,985
  11,985
D
 
ISO Stock Option (Right to Buy) $ 13           08/04/1999 10/18/2005 Common Stock
7,692
  7,692
D
 
ISO Stock Option (Right to Buy) $ 14.5           08/04/1999 08/21/2006 Common Stock
27,584
  27,584
D
 

Reporting Owners

Reporting Owner Name / Address Relationships
Director 10% Owner Officer Other
ACKLEY ROBERT W
CROMPTON CORPORATION
1 EXTRUSION DRIVE
PAWCATUCK, CT 06379
      Executive V.P. - Polymer Proc.  

Signatures

Robert W. Ackley 02/11/2005
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

Note: File three copies of this Form, one of which must be manually signed. If space provided is insufficient, see Instruction 6 for procedure.

Potential persons who are to respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB number.