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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1. Name and Address of Reporting Person * FLORENCE WALTER C   2. Issuer Name and Ticker or Trading Symbol SI INTERNATIONAL INC [SINT] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 135 S. LASALLE STREET, SUITE 3800 3. Date of Earliest Transaction (Month/Day/Year) 07/28/2005 (Street) CHICAGO, IL 60603-4131 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, par value $0.01 per share 07/28/2005 07/28/2005 J(1)   312,500 D $ 31.65 312,836 (2) I See footnote (3) Common Stock, par value $0.01 per share 07/28/2005 07/28/2005 S(4)   15,625 D $ 31.6198 15,659 (2) I See footnote (3) Common Stock, par value $0.01 per share               53 (2) D   Common Stock, par value $0.01 per share 07/28/2005 07/28/2005 J(5)   25,000 A $ 31.65 25,158 (5) I See footnote (3) Common Stock, par value $0.01 per share 07/28/2005 07/28/2005 J(5)   25,158 D $ 31.65 0 (5) I See footnote (3)

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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

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
FLORENCE WALTER C 135 S. LASALLE STREET, SUITE 3800 CHICAGO, IL 60603-4131	X

Signatures

Karen C. Fanelli, under Power of Attorney for Walter C. Florence		08/01/2005
**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)	Frontenac VII LP ("FVII") distributed 312,500 shares of Common Stock of the Issuer on July 28, 2005. After such disposition, FVII holds 312,836 shares of Common Stock of the Issuer.
(2)	After giving effect to all the transactions reported herein, Mr. Florence may be deemed to beneficially own 328,548 shares of Common Stock of the Issuer (excluding shares issuable upon exercise of stock options), which includes 312,836 shares held by FVII, 15,659 shares held by Frontenac Masters VII LP ("Masters"), and 53 shares owned directly by Mr. Florence.
(3)	Mr. Florence is associated with Frontenac Company VII, LLC ("Frontenac LLC"), the general partner of FVII and the general partner of Masters. Mr. Florence disclaims beneficial ownership of the shares held by FVII and Masters except to the extent of his pecuniary interest in Masters arising from his role as a limited partner in such entity. The filing of this form shall not be deemed to be an admission that Mr. Florence is, for purposes of Section 16 or otherwise, the beneficial owner of such shares.
(4)	Masters disposed of 15,625 shares of Common Stock of the Issuer on July 28, 2005. After such disposition, Masters holds 15,659 shares of Common Stock of the Issuer.
(5)	On July 28, 2005, FVII distributed 25,000 shares to Frontenac LLC, who then distributed 25,158 shares to its members. After such distribution, Frontenac LLC holds no shares of Common Stock of the Issuer.

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