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 *
VAGNINI MICHAEL F
   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)
VP and Controller
(Last)
(First)
(Middle)
3. Date of Earliest Transaction (Month/Day/Year)
05/02/2005
(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               3,389 D  
Common Stock 05/05/2005   J(1)   93 A $ 0 4,568 I ESOP TRUST
Common Stock 05/05/2005   J(2)   14.1726 A $ 0 167.6684 I DRIP
Common Stock 05/02/2005   J(3)   19,120 D $ 13.97 44,365 I LTIP Trust
Common Stock 05/03/2005   J(4)   200 D $ 14.13 44,165 I LTIP Trust
Common Stock 05/05/2005   J(5)   238 A $ 0 44,403 I LTIP Trust
Common Stock               7,707 I Restricted Stock Account
Common Stock               6,500 I Restricted Stock Account II
Common Stock               7,000 I Restricted Stock Account III

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 13,812   13,812 D  
NQ Stock Option (Right to Buy) $ 6.38             01/21/2004 02/20/2013 Common Stock 5,690   5,690 D  
NQ Stock Option (Right to Buy) $ 7.25             10/22/2003 10/22/2012 Common Stock 7,132   7,132 D  
NQ Stock Option (Right to Buy) $ 7.92             10/23/2002 11/22/2011 Common Stock 10,000   10,000 D  
NQ Stock Option (Right to Buy) $ 8.1562             10/31/2001 11/30/2010 Common Stock 20,000   20,000 D  
NQ Stock Option (Right to Buy) $ 8.343             10/19/2000 11/19/2009 Common Stock 40,473   40,473 D  
NQ Stock Option (Right to Buy) $ 11.24             11/23/2005 12/22/2014 Common Stock 25,000   25,000 D  
NQ Stock Option (Right to Buy) $ 12.92             02/23/2006 03/22/2015 Common Stock 21,000   21,000 D  
NQ Stock Option (Right to Buy) $ 14.3438             08/04/1999 11/14/2008 Common Stock 727   727 D  
ISO Stock Option (Right to Buy) $ 5.85             10/20/2004 10/19/2013 Common Stock 6,188   6,188 D  
ISO Stock Option (Right to Buy) $ 6.38             01/21/2004 01/21/2013 Common Stock 24,310   24,310 D  
ISO Stock Option (Right to Buy) $ 7.25             10/22/2003 10/22/2012 Common Stock 12,868   12,868 D  
ISO Stock Option (Right to Buy) $ 7.92             10/23/2003 10/23/2011 Common Stock 10,000   10,000 D  
ISO Stock Option (Right to Buy) $ 8.343             10/19/2001 10/19/2009 Common Stock 9,527   9,527 D  
ISO Stock Option (Right to Buy) $ 14.3438             08/04/1999 10/14/2008 Common Stock 7,273   7,273 D  
ISO Stock Option (Right to Buy) $ 16.875             08/04/1999 11/16/2006 Common Stock 5,000   5,000 D  
ISO Stock Option (Right to Buy) $ 26.4063             08/04/1999 11/07/2007 Common Stock 5,000   5,000 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
VAGNINI MICHAEL F

MIDDLEBURY, CT 06749		       VP and Controller  

Signatures

 Michael F. Vagnini   05/05/2005
**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) 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.
(2) These shares were acquired during the fiscal year pursuant to the Registrant's Dividend Reinvestment Plan and through the reinvestment of dividends paid on the shares in this fund.
(3) 19,120 shares were distributed to the reporting person in accordance with the LTIP Plan of which all 19,120 shares were withheld to satisfy tax withholding requirements. It is anticipated that 44,403 shares, representing the balance of the shares in the LTIP account, will be transferred to the reporting person on or about May 9, 2005.
(4) 200 shares were distributed to the reporting person in accordance with the LTIP Plan of which all 200 shares were withheld to satisfy tax withholding requirements. It is anticipated that 44,403 shares, representing the balance of the shares in the LTIP account, will be transferred to the reporting person on or about May 9, 2005.
(5) These shares were acquired during the fiscal year pursuant to the 1988 Long Term Incentive Plan and through reinvestment of dividends paid on the shares in this fund.

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