FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue.SeeInstruction 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 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*
COHEN AVI
2. Issuer NameandTicker or Trading Symbol
KLA TENCOR CORP [KLAC]		 5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____导演 _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
VP, Pattern Solutions Group
(Last)
(First)
(Middle)
C/O KLA-TENCOR CORPORATION, 160 RIO ROBLES		 3. Date of Earliest Transaction (Month/Day/Year)
01/27/2004
(街)

SAN JOSE, CA 95130		 4. If Amendment, Date Original Filed(Month/Day/Year)
 6. Individual or Joint/Group Filing(检查适用线)
_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 1,145 D

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
Non-Qualified Stock Option (right to buy) $ 58.10 01/27/2004 A 8,000 10/27/2004 01/27/2014 Common Stock 8,000 $ 0 8,000 D
Non-Qualified Stock Option (right to buy) $ 10.63 08/31/1999 08/31/2008 Common Stock 47,313 47,313 D
Non-Qualified Stock Option (right to buy) $ 22.25 04/30/1998 04/30/2007 Common Stock 7,500 7,500 D
Non-Qualified Stock Option (right to buy) $ 26.25 11/10/2001 11/10/2010 Common Stock 8,750 8,750 D
Non-Qualified Stock Option (right to buy) $ 29.31 10/02/2002 10/02/2011 Common Stock 22,500 22,500 D
Non-Qualified Stock Option (right to buy) $ 32.75 04/04/2002 04/04/2011 Common Stock 8,750 8,750 D
Non-Qualified Stock Option (right to buy) $ 33.75 10/27/2000 10/27/2009 Common Stock 24,000 24,000 D
Non-Qualified Stock Option (right to buy) $ 34.67 11/08/2003 01/28/2013 Common Stock 12,500 12,500 D
Non-Qualified Stock Option (right to buy) $ 37.05 11/08/2003 11/08/2012 Common Stock 6,250 6,250 D
Non-Qualified Stock Option (right to buy) $ 44.6875 08/13/2001 08/13/2010 Common Stock 17,500 17,500 D
Non-Qualified Stock Option (right to buy) $ 51.229 11/08/2003 07/30/2013 Common Stock 6,250 6,250 D
Non-Qualified Stock Option (right to buy) $ 53.86 10/27/2004 10/27/2013 Common Stock 16,000 16,000 D

Reporting Owners

Reporting Owner Name / Address Relationships
Director 10% Owner Officer Other
COHEN AVI
C/O KLA-TENCOR CORPORATION
160 RIO ROBLES
SAN JOSE, CA 95130		 VP, Pattern Solutions Group

Signatures

By: Stuart J. Nichols For: Avi Cohen 01/28/2004
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person,seeInstruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations.See18 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 is insufficient,seeInstruction 6 for procedure.

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