FORM 5 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b). Form 3 Holdings Reported Form 4 Transactions Reported

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 ANNUAL 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

OMB APPROVAL OMB Number: 3235-0362 Expires: January 31, 2005 Estimated average burden hours per response... 1.0

1. Name and Address of Reporting Person * WEST ALFRED P JR 2. Issuer Name and Ticker or Trading Symbol SEI INVESTMENTS CO [SEIC] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director __X__ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) ONE FREEDOM VALLEY DRIVE 3. Statement for Issuer's Fiscal Year Ended (Month/Day/Year) 12/31/2009 (Street) OAKS, PA 19456 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Reporting (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 at end of Issuer's Fiscal Year (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Amount (A) or (D) Price Common Stock 12/04/2006   G5 236,492 (1) D $ 0 16,229,990 D   Common Stock 01/22/2007   G5 29,006 (2) D $ 0 16,200,984 D   Common Stock 02/08/2007   G5 94,938 (3) D $ 0 16,106,046 D   Common Stock 12/04/2007   G5 2,252 D $ 0 16,103,794 D   Common Stock 12/04/2007   G5 6,992 D $ 0 16,096,802 D   Common Stock 12/10/2007   G5 192,006 D $ 0 15,904,796 D   Common Stock 06/05/2008   G5 20,231 D $ 0 15,884,565 D   Common Stock 12/11/2008   G5 13,200 D $ 0 15,871,365 D   Common Stock 06/02/2009   G5 165,915 D $ 0 15,705,450 D   Common Stock 07/27/2009   G5 13,809 D $ 0 15,691,641 D   Common Stock 12/10/2009   G5 13,750 D $ 0 15,677,891 D   Common Stock 12/10/2009   G5 163,664 D $ 0 15,514,227 (4) D Â

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.

SEC 2270 (9-02)

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 at End of Issuer's Fiscal Year (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
WEST ALFRED P JR ONE FREEDOM VALLEY DRIVE OAKS, PA 19456	  X	  X	Â	Â

Signatures

Ruth Montgomery (Attorney in Fact)		04/09/2010
**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 reporting person gifted a total of 118,246 shares of common stock of SEI Investments Company ("SEI") on December 4, 2006. SEI subsequently approved a two-for-one split of its outstanding common stock effective as of June 8, 2007. As a result, this gift is reported on this Form 5 as a gift of 236,492 shares, which is the post-split equivalent of the actual amount of gifted shares.
(2)	The reporting person gifted a total of 14,503 shares of common stock of SEI on January 22, 2007. SEI subsequently approved a two-for-one split of its outstanding common stock effective as of June 8, 2007. As a result, this gift is reported on this Form 5 as a gift of 29,006 shares, which is the post-split equivalent of the actual amount of gifted shares.
(3)	The reporting person gifted a total of 47,469 shares of common stock of SEI on February 8, 2007. SEI subsequently approved a two-for-one split of its outstanding common stock effective as of June 8, 2007. As a result, this gift is reported on this Form 5 as a gift of 94,938 shares, which is the post-split equivalent of the actual amount of gifted shares.
(4)	Reflects the total number of shares owned by the reporting person taking into account the following: (i) the gifts of 952,255 shares, in aggregate, reported on this Form 5, (ii) 4,714 shares inadvertently over-reported by the reporting person on a form 4 originally filed on 9/13/2007 and amended on the date of this report (iii) 30,090 shares inadvertently over-reported by the reporting person on a form 4 originally filed on 8/5/2008 and amended on the date of this report, (iv) 258,794 shares inadvertently over-reported by the reporting person on a form 4 originally filed on 5/8/2009 and amended on the date of this report, (v) 728 shares inadvertently over-reported by the reporting person on a form 4 originally filed on 6/22/2009 and amended on the date of this report, and (vi) 48 shares previously inadvertently reported as being directly owned by the reporting person.

Note: File three copies of this Form, one of which must be manually signed. If space provided is insufficient, see Instruction 6 for procedure.

Potential persons who are to respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB number.