EXHIBIT 3.1

                              ARTICLES OF AMENDMENT
                                     TO THE
                        AMENDED ARTICLES OF INCORPORATION
                       OF NATURAL GAS SERVICES GROUP, INC.

         Pursuant to the provisions of the Colorado  Business  Corporation  Act,
the undersigned  Corporation  adopts the following  Articles of Amendment to its
Amended Articles of Incorporation:


         FIRST: The name of the Corporation is Natural Gas Services Group, Inc.

         SECOND:   The   following   amendment   to  the  Amended   Articles  of
Incorporation  was duly adopted by a vote of the  shareholders at a meeting held
on June 18, 2003,  and the number of votes cast for the amendment by each voting
group was sufficient for approval by that voting group.

         The first  paragraph  of Section  II.6 of Article II of the Articles of
Incorporation  is  hereby  amended  to  change  the  number  of  shares  of  10%
Convertible Series A Preferred Stock from 1,177,000 to 381,654.

         The (a) name,  and (b) mailing  address,  of the  individual who caused
this document to be delivered for filing, and to whom the Secretary of State may
deliver  notice of filing if this  document is refused,  is: Scott W.  Sparkman,
Secretary,  Natural  Gas  Services  Group,  Inc.,  2911 South  County Road 1260,
Midland, Texas 79706