Ownership Submission
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 *
  McCullough Natalie A
 2. Date of Event Requiring Statement (Month/Day/Year)
03/24/2011		 3. Issuer Name and Ticker or Trading Symbol
SERVICESOURCE INTERNATIONAL, INC. [SREV]
(Last)
(First)
(Middle)
C/O SERVICESOURCE INTERNATIONAL, INC., 634 SECOND STREET		 4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
Chief Marketing Officer
 5. If Amendment, Date Original Filed(Month/Day/Year)
(Street)

SAN FRANCISCO, CA 94107		 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)

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) 06/01/2014 Common Stock 80,000 $ 1.49 D  
Employee Stock Option (right to buy)   (2) 01/30/2018 Common Stock 20,000 $ 4.26 D  
Employee Stock Option (right to buy)   (3) 06/01/2014 Common Stock 40,000 $ 4.26 D  
Employee Stock Option (right to buy)   (4) 11/04/2019 Common Stock 100,000 $ 4.6 D  
Employee Stock Option (right to buy)   (5) 02/09/2020 Common Stock 60,000 $ 4.65 D  
Employee Stock Option (right to buy)   (6) 12/16/2020 Common Stock 75,000 $ 5.8 D  

Reporting Owners

Reporting Owner Name / Address Relationships
Director 10% Owner Officer Other
McCullough Natalie A
C/O SERVICESOURCE INTERNATIONAL, INC.
634 SECOND STREET
SAN FRANCISCO, CA 94107		       Chief Marketing Officer  

Signatures

/s/ Paul D. Warenski, by power of attorney 03/24/2011
**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) Shares subject to the option are fully vested and immediately exercisable.
(2) The option is subject to an early exercise provision and is immediately exercisable. Twenty-five percent of the shares subject to the option vested on January 1, 2009 and 2.083% of the shares vest monthly thereafter.
(3) Twenty-five percent of the shares subject to the option vested on November 1, 2009 and 2.083% of the shares vest monthly thereafter.
(4) Twenty-five percent of the shares subject to the option vested on November 4, 2010 and one forty-eighth of the shares vest monthly thereafter.
(5) One-fourth of the shares subject to the option vest on January 27, 2011 and one forty-eighth of the shares vest monthly thereafter.
(6) One-fourth of the shares subject to the option vest on December 16, 2011 and one forty-eighth of the shares vest monthly thereafter.
 
Remarks:
Exhibit 24 - Power of Attorney

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