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 * SELLERS WALLACE O   2. Issuer Name and Ticker or Trading Symbol NATURAL GAS SERVICES GROUP INC [NGS] 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) 6539 UPPER YORK RD 3. Date of Earliest Transaction (Month/Day/Year) 01/31/2005 (Street) SOLEBURY, PA 18963 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               196,091 I By Trust (1) Common Stock               196,091 I By Trust (2) Common Stock               103,909 D   Common Stock               158,600 I By Wife Common Stock 01/31/2005   X   21,936 A $ 2.5 21,936 D   Common Stock 01/31/2005   X   9,032 A $ 3.25 9,032 D

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

Nonqualified Stock Option (right to buy) (3)

$ 3.88

12/31/2002

12/31/2012

Common Stock

2,500

2,500

D

Stock Warrant (right to buy)

$ 2.5

01/31/2005

X

21,936

03/31/2001

12/31/2006

Common Stock

21,936

$ 0

0

D

Stock Warrant (right to buy)

$ 3.25

01/31/2005

X

9,032

04/24/2002

04/23/2007

Common Stock

9,032

$ 0

0

D

Nonqualified Stock Option (right to buy) (3)

$ 5.55

12/31/2003

12/31/2013

Common Stock

2,500

2,500

D

Nonqualified Stock Option (right to buy) (3)

$ 9.34

01/05/2005

01/05/2015

Common Stock

2,500

2,500

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
SELLERS WALLACE O 6539 UPPER YORK RD SOLEBURY, PA 18963	X	X

Signatures

/s/ Wallace O. Sellers		02/02/2005
**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)	These shares are held and registered in the name of a trust entitled "Trust under deed of Wallace O. Sellers dated June 21, 1991," under which the reporting person's spouse, Naudain Sellers, is a contingent remainder beneficiary. An unrelated third party serves as trustee of this Trust and possesses exclusive control over the investment of the securities therein. The reporting person disclaims beneficial ownership of these securities, and the filing is not an admission that the reporting person is the beneficial owner of these securities for purposes of Section 16 or for any other purpose.
(2)	These shares are held by and registered in the name of a trust entitled "Trust under deed of Wallace O. Sellers dated June 22, 1971," under which the reporting person's spouse, Naudain Sellers, is a beneficiary during her lifetime. An unrelated third party serves as trustee of this Trust and possesses exclusive control over the investment of the securities therein. The reporting person disclaims beneficial ownership of these securities, and the filing is not an admission that the reporting person is the beneficial owner of these securities for purposes of Section 16 or for any other purpose.
(3)	Such options were granted to the reporting person under the Natural Gas 1998 Stock Option Plan.

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