FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF 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 *   Grantham Donald C 2. Date of Event Requiring Statement (Month/Day/Year) 04/27/2006 3. Issuer Name and Ticker or Trading Symbol SUN MICROSYSTEMS, INC. [SUNW] (Last) (First) (Middle) 4150 NETWORK CIRCLE 4. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) EVP, Global Sales & Services 5. If Amendment, Date Original Filed(Month/Day/Year) (Street) SANTA CLARA, CA 95054 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 Beneficially Owned

1.Title of Security (Instr. 4) 2. Amount of Securities Beneficially Owned (Instr. 4) 3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 4. Nature of Indirect Beneficial Ownership (Instr. 5) Common Stock 222,254 D Â

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.			SEC 1473 (7-02)
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Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Employee Stock Option (Right to Buy) (1)	  (2)	11/10/2007	Common Stock	28,000	$ 28.0782	D	Â
Employee Stock Option (Right to Buy) (1)	  (2)	04/12/2008	Common Stock	14,000	$ 40	D	Â
Employee Stock Option (Right to Buy) (1)	  (2)	10/11/2008	Common Stock	30,000	$ 50.9375	D	Â
Employee Stock Option (Right to Buy) (1)	  (2)	04/18/2009	Common Stock	20,000	$ 18.58	D	Â
Employee Stock Option (Right to Buy) (1)	  (2)	06/13/2009	Common Stock	20,000	$ 16.25	D	Â
Employee Stock Option (Right to Buy) (1)	  (2)	09/27/2009	Common Stock	15,000	$ 7.91	D	Â
Employee Stock Option (Right to Buy) (1)	  (2)	11/07/2009	Common Stock	20,000	$ 12.59	D	Â
Employee Stock Option (Right to Buy) (1)	  (2)	11/07/2009	Common Stock	20,000	$ 12.59	D	Â
Employee Stock Option (Right to Buy) (1)	  (2)	03/19/2010	Common Stock	200	$ 9.14	D	Â
Employee Stock Option (Right to Buy) (1)	  (2)	03/19/2010	Common Stock	20,000	$ 9.14	D	Â
Employee Stock Option (Right to Buy) (1)	  (2)	03/19/2010	Common Stock	50,000	$ 9.14	D	Â
Employee Stock Option (Right to Buy) (1)	  (2)	05/14/2010	Common Stock	50,000	$ 7.07	D	Â
Employee Stock Option (Right to Buy) (1)	  (3)	07/25/2010	Common Stock	6,000	$ 3.7	D	Â
Employee Stock Option (Right to Buy) (1)	  (4)	07/25/2010	Common Stock	75,000	$ 3.7	D	Â
Employee Stock Option (Right to Buy) (1)	  (5)	05/21/2011	Common Stock	20,000	$ 4.2	D	Â
Employee Stock Option (Right to Buy) (1)	  (6)	05/21/2011	Common Stock	45,000	$ 4.2	D	Â
Employee Stock Option (Right to Buy) (1)	  (7)	11/13/2011	Common Stock	50,000	$ 4.208	D	Â
Employee Stock Option (Right to Buy) (1)	  (8)	09/17/2012	Common Stock	60,000	$ 3.94	D	Â
Employee Stock Option (Right to Buy) (1)	  (9)	01/27/2013	Common Stock	150,000	$ 4.12	D	Â
Employee Stock Option (Right to Buy) (1)	  (10)	04/28/2013	Common Stock	250,000	$ 3.44	D	Â
Employee Stock Option (Right to Buy) (1)	  (11)	07/28/2013	Common Stock	300,000	$ 3.85	D	Â

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Grantham Donald C 4150 NETWORK CIRCLE SANTA CLARA, CA 95054	Â	Â	  EVP, Global Sales & Services	Â

Signatures

/s/ Donald C. Grantham		05/01/2006
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 5(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)	This option was granted under the Sun Microsystems, Inc. 1990 Long-Term Equity Incentive Plan.
(2)	Immediately.
(3)	A total of 3,600 shares are fully vested and exercisable with the remaining 2,400 shares becoming exercisable as follows: (i) 1,200 shares on July 25, 2006 and (ii) 1,200 shares on July 25, 2007.
(4)	A total of 45,000 shares are fully vested and exercisable with the remaining 30,000 shares becoming exercisable as follows: (i) 15,000 shares on July 25, 2006 and (ii) 15,000 shares on July 25, 2007.
(5)	A total of 8,000 shares are fully vested and exercisable with the remaining 12,000 shares becoming exercisable as follows: (i) 4,000 shares on May 21, 2006; (ii) 4,000 shares on May 21, 2007; and (iii) 4,000 shares on May 21, 2008.
(6)	A total of 18,000 shares are fully vested and exercisable with the remaining 27,000 shares becoming exercisable as follows: (i) 9,000 shares on May 21, 2006; (ii) 9,000 shares on May 21, 2007; and (iii) 9,000 shares on May 21, 2008.
(7)	A total of 20,000 shares are fully vested and exercisable with the remaining 30,000 shares becoming exercisable as follows: (i) 10,000 shares on November 13, 2006; (ii) 10,000 shares on November 13, 2007; and (iii) 10,000 shares on November 13, 2008.
(8)	A total of 12,000 shares are fully vested and exercisable with the remaining 48,000 shares becoming exercisable as follows: (i) 12,000 shares on September 17, 2006; (ii) 12,000 shares on September 17, 2007; (iii) 12,000 shares on September 17, 2008; and (iv) 12,000 shares on September 17, 2009.
(9)	A total of 30,000 shares are fully vested and exercisable with the remaining 120,000 shares becoming exercisable as follows: (i) 30,000 shares on January 27, 2007; (ii) 30,000 shares on January 27, 2008; (iii) 30,000 shares on January 27, 2009; and (iv) 30,000 shares on January 27, 2010.
(10)	A total of 50,000 shares are fully vested and exercisable with the remaining 200,000 shares becoming exercisable as follows: (i) 50,000 shares on April 28, 2007; (ii) 50,000 shares on April 28, 2008; (iii) 50,000 shares on April 28, 2009; and (iv) 50,000 shares on April 28, 2010.
(11)	This option vests and becomes exercisable in five equal annual installments of 60,000 shares beginning on July 28, 2006.

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