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
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1. Name and Address of Reporting Person *
RUCK WALTER K
 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)
SVP Euro, Africa & M.D.
(Last)
(First)
(Middle)

BENSON ROAD		 3. Statement for Issuer's Fiscal Year Ended (Month/Day/Year)
12/31/2004
(Street)


MIDDLEBURY, CT 06749		 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             46,877 D  
Common Stock             9,696.9688 I ESOP TRUST
Common Stock             20,551 I LTIP Trust

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
19,265
  19,265
D
 
NQ Stock Option (Right to Buy) $ 6.38           01/21/2004 02/20/2013 Common Stock
10,690
  10,690
D
 
NQ Stock Option (Right to Buy) $ 7.25           10/22/2003 11/21/2012 Common Stock
9,863
  9,863
D
 
NQ Stock Option (Right to Buy) $ 7.92           10/23/2002 11/22/2011 Common Stock
12,500
  12,500
D
 
NQ Stock Option (Right to Buy) $ 8.1562           10/31/2001 11/30/2010 Common Stock
30,000
  30,000
D
 
NQ Stock Option (Right to Buy) $ 8.343           10/19/2000 11/19/2009 Common Stock
81,244
  81,244
D
 
NQ Stock Option (Right to Buy) $ 14.3438           08/05/1999 11/14/2008 Common Stock
26,062
  26,062
D
 
NQ Stock Option (Right to Buy) $ 26.4063           08/04/1999 11/07/2007 Common Stock
10,722
  10,722
D
 
ISO Stock Option (Right to Buy) $ 5.85           10/20/2004 10/19/2013 Common Stock
735
  735
D
 
ISO Stock Option (Right to Buy) $ 6.38           01/21/2004 01/21/2013 Common Stock
34,310
  34,310
D
 
ISO Stock Option (Right to Buy) $ 7.25           10/22/2003 10/22/2012 Common Stock
10,137
  10,137
D
 
ISO Stock Option (Right to Buy) $ 7.92           10/23/2003 10/23/2011 Common Stock
12,500
  12,500
D
 
ISO Stock Option (Right to Buy) $ 8.343           10/19/2001 10/19/2009 Common Stock
18,756
  18,756
D
 
ISO Stock Option (Right to Buy) $ 14.3438           08/04/1999 10/14/2008 Common Stock
3,938
  3,938
D
 
ISO Stock Option (Right to Buy) $ 14.5           08/04/1999 08/21/2006 Common Stock
15,000
  15,000
D
 
ISO Stock Option (Right to Buy) $ 26.4063           08/04/1999 10/07/2007 Common Stock
4,278
  4,278
D
 

Reporting Owners

Reporting Owner Name / Address Relationships
Director 10% Owner Officer Other
RUCK WALTER K
BENSON ROAD
MIDDLEBURY, CT 06749		       SVP Euro, Africa & M.D.  

Signatures

Walter K. Ruck 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.

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