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

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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(Print or Type Responses)
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)
Euro, Africa & M.D.
(Last)
(First)
(Middle)
BENSON ROAD
3. Date of Earliest Transaction (Month/Day/Year)
02/01/2005
(Street)

MIDDLEBURY, CT 06749
4. If Amendment, Date Original Filed(Month/Day/Year)
6. Individual or Joint/Group Filing(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 Following Reported Transaction(s)
(Instr. 3 and 4)
6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)
7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Stock 02/01/2005   J(1)   3,003 A $ 11.17 49,880 D  
Common Stock 02/01/2005   J(2)   51.3346 A $ 0 9,701.8816 I ESOP TRUST
Common Stock 02/01/2005   J(3)   5,136 D $ 11.17 14,864 I LTIP Trust
Common Stock 02/01/2005   J(4)   551 A $ 11.17 15,415 I LTIP Trust

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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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 Following Reported Transaction(s)
(Instr. 4)
10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)
11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (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  
NQ Rights Option $ 13.5742 02/01/2005   J(5)     4,796 08/21/1996 09/30/2004 Common Stock 4,796 $ 0 0 D  

Reporting Owners

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

Signatures

 Walter K. Ruck   02/02/2005
**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).
(1) Direct holdings increased by 3,003 shares transferred from the 2004-2006 Long Term Incentive Plan (LTIP Trust).
(2) These shares were acquired during the fiscal year pursuant to the Registrant's Employee Stock Ownership Plan (ESOP Trust) and through reinvestment of dividends paid on the shares in this fund.
(3) 5,136 Shares were distributed to the reporting person in accordance with the 2004-2006 Long Term Incentive Plan (from Restricted Stock Account I) of which 2,133 shares were withheld to satisfy tax withholding requirements.
(4) These shares were acquired during the fiscal year pursuant to the 2004-2006 Long Term Incentive Plan and through reinvestment of dividends paid on the shares in this fund.
(5) Expired by its term without exercise or payment.

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