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 * MORGANS DAVID J JR   2. Issuer Name and Ticker or Trading Symbol CYTOKINETICS INC [CYTK] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) SVP-Drug Discovery and Dev (Last) (First) (Middle) 280 EAST GRAND AVENUE 3. Date of Earliest Transaction (Month/Day/Year) 08/18/2006 (Street) SOUTH SAN FRANCISCO, CA 94080 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 08/18/2006   M(1)   5,000 A $ 1.2 50,000 D   Common Stock 08/18/2006   S(2)   5,000 D $ 6 45,000 D

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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

Incentive Stock Option (right to buy)

$ 1.2

08/18/2006

M

5,000

07/10/2002(3)

07/10/2012

Common Stock

5,000

$ 0

30,000

D

Incentive Stock Option (right to buy)

$ 1.2

05/21/2003(4)

05/21/2013

Common Stock

54,500

54,500

D

Incentive Stock Option (right to buy)

$ 6.5

04/08/2004(5)

03/08/2014

Common Stock

34,000

34,000

D

Incentive Stock Option (right to buy)

$ 6.59

04/11/2005(6)

04/11/2015

Common Stock

35,995

35,995

D

Incentive Stock Option (right to buy)

$ 7.15

03/01/2006(7)

03/01/2016

Common Stock

15,388

15,388

D

Non-Qualified Stock Option (right to buy)

$ 6.59

04/11/2005(6)

04/11/2015

Common Stock

14,005

14,005

D

Non-Qualified Stock Option (right to buy)

$ 7.15

03/01/2006(7)

03/01/2016

Common Stock

44,612

44,612

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
MORGANS DAVID J JR 280 EAST GRAND AVENUE SOUTH SAN FRANCISCO, CA 94080			SVP-Drug Discovery and Dev

Signatures

By: James H. Sabry, M.D., Ph.D. For: David J. Morgans, Jr., Ph.D.		08/18/2006
**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)	The exercise reported in this Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on November 15, 2005.
(2)	The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on November 15, 2005.
(3)	This option is immediately exercisable upon grant and shall vest as to 833 shares on 04/15/02 and the balance of 49,167 divided into equal monthly installments thereafter such that the option shall be 100% vested on 03/15/07.
(4)	This option is immediately exercisable upon grant and shall vest as to 1,135 shares on 04/01/03 and the balance of 53,365 divided into equal monthly installments thereafter such that the option shall be 100% vested on 03/01/07.
(5)	This option shall vest and become exercisable as to 708 shares on 04/08/04 and the balance of 33,292 divided into equal monthly installments thereafter such that the option shall be 100% vested on 03/08/08.
(6)	When the ISO and NQ dated 04/11/05 are combined for a total grant of 50,000 shares, the option shall vest and become exercisable as to 50,000 shares divided into equal monthly installments such that the option shall be 100% vested on 03/01/2009.
(7)	When the ISO and NQ dated 03/01/2006 are combined for a total grant of 60,000 shares, the option shall vest and become exercisable as to 60,000 shares divided into equal monthly installments such that the option shall be 100% vested on 03/01/2010.

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