Exhibit 10.2


THIS OPTION GRANTED HEREBY IS NONTRANSFERABLE  OTHER THAN BY WILL OR THE LAWS OF
DESCENT  AND  DISTRIBUTION  AND THE  SHARES  UNDERLYING  SUCH  OPTION MAY NOT BE
OFFERED FOR SALE, SOLD OR OTHERWISE  TRANSFERRED EXCEPT PURSUANT TO AN EFFECTIVE
REGISTRATION  STATEMENT  UNDER  THE  SECURITIES  ACT OF 1933 OR  PURSUANT  TO AN
EXEMPTION FROM  REGISTRATION  UNDER SUCH ACT, THE AVAILABILITY OF WHICH IS TO BE
ESTABLISHED TO THE SATISFACTION OF NATURAL GAS SERVICES GROUP, INC.

                       NONSTATUTORY STOCK OPTION AGREEMENT

         THIS  NONSTATUTORY  STOCK OPTION  AGREEMENT  (this  "Agreement"),  made
effective as of the 24th day of August,  2005,  is between  Natural Gas Services
Group, Inc., a Colorado  corporation (the "Company"),  and Stephen C. Taylor, an
employee of the Company ("Employee").

         As an inducement  material to entering into employment with the Company
and in  consideration  of the  mutual  agreements  and other  matters  set forth
herein, the Company and Employee hereby agree as follows:

         1. Grant of Option. The Company hereby irrevocably grants to Employee a
nonstatutory  stock  option  (this  "Option")  to purchase all or any part of an
aggregate of 45,000 shares of the common stock of the Company (the "Stock"),  on
the terms and conditions set forth herein.  This Option is a nonstatutory  stock
option and not an incentive  stock  option  within the meaning of Section 422 of
the Internal Revenue Code of 1986, as amended (the "Code").

         2. Purchase Price.  The purchase price of Stock  purchased  pursuant to
the exercise of this Option shall be $9.22 per share,  which has been determined
to be the Fair  Market  Value of the Stock at  January  13,  2005,  the date the
Company employed the Employee.  "Fair Market Value" of the Stock for purposes of
this  Agreement  shall mean the  closing  price of the Stock as  reported by the
American Stock Exchange on the date the Fair MarketValue is to be determined.

         3. Exercise of Option. Subject to the earlier expiration of this Option
as herein  provided,  this  Option may be  exercised  by  written  notice to the
Company at its  principal  executive  office  addressed to the  attention of the
Chairman of the Board of  Directors  of the Company at any time and from time to
time  after  the  expiration  of six  months  and one day from the date of grant
hereof,  but,  except as  otherwise  provided  below,  this Option  shall not be
exercisable  for more  than the  percentage  of the  aggregate  number of shares
offered by this  Option  determined  by the number of partial or full years from
January 13, 2005,  the date the Company  employed the  Employee,  to the date of
such  exercise  during  which  the  Employee  is  employed  by the  Company,  in
accordance with the following schedule:




                                      -1-


- ----------------------------------------- --------------------------------------
Date of Exercise                          Percentage of Shares That May
                                          be Purchased
- ----------------------------------------- --------------------------------------
Less than 1 year                          0%
- ----------------------------------------- --------------------------------------
1 year                                    33.333%
- ----------------------------------------- --------------------------------------
2 years                                   33.333%
- ----------------------------------------- --------------------------------------
3 years                                   33.334%
- ----------------------------------------- --------------------------------------

This  Option  shall  not be  exercisable  in  any  event  after  the  date  (the
"Expiration Date") that is ten years from the date of grant hereof. The purchase
price of shares as to which this  Option is  exercised  shall be paid in full at
the time of exercise  (a) in cash  (including  check,  bank draft or money order
payable to the order of the Company), or (b) by delivering to the Company shares
of Stock  having a fair  market  value  equal to the  purchase  price,  or (c) a
combination  of (a) and (b).  No fraction of a share of Stock shall be issued by
the Company  upon  exercise of this Option or accepted by the Company in payment
of the exercise price thereof; rather, Employee shall provide a cash payment for
such amount as is necessary to effect the issuance and  acceptance of only whole
shares of Stock.  This Option shall be exercised only for 100 shares of Stock or
a  multiple  thereof  or for the full  number  of  shares of Stock for which the
Option is then  exercisable.  Unless  and until a  certificate  or  certificates
representing  such shares  shall have been  issued by the  Company to  Employee,
Employee  (or the  person  permitted  to  exercise  this  Option in the event of
Employee's  death)  shall not be or have any of the  rights or  privileges  of a
shareholder of the Company with respect to shares acquirable upon an exercise of
this Option.

         4.  Incapacitation of the Employee.  If the Employee's  employment with
the Company is  terminated  as a result of the mental or physical  incapacity or
inability of the employee to perform his duties, this Option shall automatically
fully  vest on the date of such  termination  and  shall,  Subject  to Section 3
hereof,  be  exercisable  by the  Employee,  or personal  representative  of the
Employee  until the earlier of the date that is three  months  after the date of
such  termination  or the  Expiration  Date.  If the  Employee,  or the personal
representative  of the  Employee,  fails to exercise this Option within the time
period  specified in the  preceding  sentence,  the Option  shall  automatically
terminate.

         5.  Retirement  of  Employee.  If the  Employee's  employment  with the
Company  terminates by reason of  retirement of the Employee,  this Option shall
automatically  fully vest on the date of such termination and shall,  subject to
Section 3 hereof,  be  exercisable by the Employee until the earlier of the date
that is three months after the date of such  termination or the Expiration Date.
If the Employee  fails to exercise this Option within the time period  specified
in the preceding sentence, the Option shall automatically terminate.

         6. Death of the Employee.  If the Employee  dies during the  Employee's
employment  by  the  Company  or  within  three  months  after  the   Employee's
termination of employment as a result of incapacitation (as described in Section
4 above) or  retirement  (as  described  in Section 5 above),  this Option shall



                                      -2-


fully vest on the date of the Employee's death, unless already fully vested, and
shall,  Subject  to Section 3 hereof,  be  exercisable  in full by the  personal
representative  or administrator  of the Employee's  estate or by any person who
acquired the right to exercise this Option by bequest or  inheritance,  but only
within the period  beginning  on the date of his death and ending on the earlier
of the one year anniversary of such date or the Expiration Date.

         7. Termination of Employment.If  Employee's employment with the Company
terminates  for any reason  other than those  described  in  Sections  4, 5 or 6
above,   unless   Employee  is   terminated   for  "cause,"  this  Option  shall
automatically  fully  vest  on  the  date  of  such  termination  and  shall  be
exercisable  in full by the Employee until the earlier of the date that is three
months after the date of such  termination or the Expiration  Date. For purposes
of this Agreement, for "cause" shall mean by reason of any of the following: (a)
the Employee's  conviction  of, or plea of nolo  contendere to, any felony or to
any crime or  offense  causing  substantial  harm to the  Company  or any of its
subsidiaries or affiliates  (whether or not for personal gain) or involving acts
of  theft,  fraud,  embezzlement,   moral  turpitude  or  similar  conduct;  (b)
malfeasance in the conduct of the Employee's duties,  including, but not limited
to, (i) willful and  intentional  misuse or diversion of any of the Company's or
it subsidiaries' or affiliates' funds, (ii) embezzlement, or (iii) fraudulent or
willful and material  misrepresentations  or concealments on any written reports
submitted to the Company or any of its subsidiaries or affiliates,  (c) material
failure to perform the duties of the Employee's  employment or material  failure
to follow or comply with the  reasonable  and lawful  written  directives of the
Board of Directors of the Company,  provided,  however,  that the Employee shall
have been informed,  in writing,  of such material failure and given a period of
not more than 60 days to remedy same;  or (d) a material  breach by the Employee
of the  provisions  of the  written  employment  agreement  then  governing  the
Employee's  employment.  If  the  Employee's  employment  with  the  Company  is
terminated  for cause,  this Option shall be  exercisable  by Employee until the
earlier of the date that is three months after the date of such  termination  or
the  Expiration  Date,  and then only as to the  number of shares of Stock  that
Employee was entitled to purchase hereunder at the time of such termination.

         8.  Fundamental  Change.  Upon the occurrence of a Fundamental  Change,
this Option shall automatically fully vest on the date that is immediately prior
to the  effective  date of such change.  For  purposes  hereof,  a  "Fundamental
Change" shall occur:  (a) with respect to the Company on the  effective  date of
any dissolution, merger, consolidation,  sale of all or substantially all of the
Company's  assets,  recapitalization  or any  other  type of  transaction  which
results in 51% or more of the  Company's  common stock being  changed  into,  or
exchanged for,  different  securities of the Company,  as  applicable,  or other
securities  or interests in other  persons or entities,  and (b) with respect to
the Employee on the effective date of any material  change in rank,  position or
responsibilities  of the  Employee or decrease in the base  compensation  of the
Employee.

         9.  Withholding  of Tax. To the extent that the exercise of this Option
or the  disposition  of shares of Stock  acquired  by  exercise  of this  Option
results in  compensation  income to  Employee  for  federal or state  income tax
purposes,  Employee shall deliver to the Company at the time of such exercise or
disposition  such  amount of money or shares of Stock as the Company may require



                                      -3-


to meet its  obligations  under  applicable  tax laws or  regulations,  and,  if
Employee  fails to do so, the Company is authorized to withhold from any cash or
Stock remuneration then or thereafter payable to Employee any tax required to be
withheld by reason of such resulting  compensation  income.  Upon an exercise of
this Option,  the Company is further authorized in its discretion to satisfy any
such withholding requirement out of any cash or shares of Stock distributable to
Employee upon such exercise.

         10. Tax Gross-Up  Payment.  If the  exercise of this Option  results in
compensation  to  Employee  taxed  at  the  federal  ordinary  income  tax  rate
(including any applicable FICA or other  income-based  taxes) then applicable to
Employee,  the Company shall pay a tax gross-up payment to Employee in an amount
sufficient to place the Employee in the same after-tax  position  Employee would
have been in had such  compensation  been taxed at the federal capital gains tax
rate then  applicable  to Employee.  All  determinations  required to be made in
connection  with the  calculation  and  payment of the tax  gross-up  payment to
Employee  shall be made by the  accounting  firm  that  prepared  the  Company's
corporate  tax  return  for the year  preceding  the year in which the  Employee
exercises this Option. Any determinations  made by such accounting firm shall be
binding on the  Employee  and the Company;  provided,  however,  if the Employee
disagrees  with the  determinations  made by the  accounting  firm, the Employee
shall have the right to verify  and appeal  such  determinations  by  delivering
written notice thereof to the Board of Directors of the Company.  Upon the Board
of Director's receipt of such notice, the Board shall make the final decision as
to the calculation and payment of the gross-up payment,  which decision shall be
binding on the  Employee and the  Company.  If the Board of  Directors  does not
receive the  Employee's  written  notice of appeal on or before the date that is
ten (10) days after the Company's delivery to the Employee of the determinations
made by the  accounting  firm, the Employee shall be deemed to have accepted and
agreed to the determinations made by the accounting firm.

         11.  Status  of  Stock.  Employee  understands  that at the time of the
execution of this  Agreement  the shares of Stock to be issued upon  exercise of
this  Option  have not been  registered  under the  Securities  Act of 1933,  as
amended (the "Act"),  or any state  securities laws. The Company may, but is not
obligated  to,  effect such a  registration  in the future.  Until the shares of
Stock  acquirable upon the exercise of this Option have been registered for sale
under the Act, the Company  will not issue such shares  unless the holder of the
Option provides the Company with a written  opinion of legal counsel,  who shall
be  satisfactory  to the Company,  addressed to the Company and  satisfactory in
form and  substance to the  Company's  counsel,  to the effect that the proposed
issuance of such shares to such Option  holder may be made without  registration
under the Act. If an exemption from registration under the Act is available upon
an exercise of this Option,  Employee (or the person  permitted to exercise this
Option in the event of Employee's  death), if requested by the Company to do so,
will execute and deliver to the Company in writing an agreement  containing such
provisions  as the  Company  may require to assure  compliance  with  applicable
securities laws.




                                      -4-


         Employee  agrees that the shares of Stock which Employee may acquire by
exercising  this Option  shall not be sold,  transferred,  assigned,  pledged or
hypothecated  in the  absence of an  effective  registration  statement  for the
shares  under the Act and  applicable  state  securities  laws or an  applicable
exemption from the registration requirements of the Act and any applicable state
securities  laws.  Employee also agrees that the shares of Stock which  Employee
may acquire by exercising this Option will not be sold or otherwise  disposed of
in any manner which would  constitute a violation of any  applicable  securities
laws,  whether  federal  or state.  In  addition,  Employee  agrees (i) that the
certificates  representing  the shares of Stock  purchased under this Option may
bear such  legend or legends  as the Board of  Directors  of the  Company or its
Compensation  Committee  deems  appropriate in order to assure  compliance  with
applicable  securities  laws,  (ii) that the Company may refuse to register  the
transfer  of the  shares  of Stock  purchased  under  this  Option  on the stock
transfer  records of the Company if such proposed  transfer would in the opinion
of counsel  satisfactory to the Company constitute a violation of any applicable
securities law and (iii) that the Company may give related  instructions  to its
transfer  agent,  if any, to stop  registration of the transfer of the shares of
Stock purchased under this Option.

         12. Nontransferability of Option. This Option may not be transferred by
Employee otherwise than by will or the laws of descent and distribution.  During
Employee's lifetime, this Option will be exercisable only by Employee.

         13.  Authority.  This Option is granted by the Company  pursuant to the
Company's general corporate powers under Sections 7-103-102 and 7-106-205 of the
Colorado Revised Statutes.

         14. Binding  Effect.  This Agreement shall be binding upon and inure to
the benefit of any successors to the Company and all persons  lawfully  claiming
under Employee.

         15.  Governing Law. This Agreement  shall be governed by, and construed
in accordance with, the laws of the State of Texas.

         IN WITNESS  WHEREOF,  the Company has caused this  Agreement to be duly
executed by its officer  thereunto  duly  authorized,  and Employee has executed
this Agreement, all as of the day and year first above written.

Dated:  August 24, 2005.


                                   NATURAL GAS SERVICES GROUP, INC.


                                   By: /s/ Wallace C. Sparkman
                                      ------------------------------------------
                                      Wallace C. Sparkman, Chairman of the Board




                                      -5-


AGREED TO:
THIS 24TH DAY OF AUGUST, 2005.

        /s/ Stephen C. Taylor
- --------------------------------------------
Stephen C. Taylor


Address:

1200 Shirley Lane
Midland, Texas 79705


ACCEPTED AND APPROVED THIS
24TH DAY OF AUGUST, 2005.


By:      /s/ William F. Hughes, Jr.
   -----------------------------------------
         William F. Hughes, Jr.
         Chairman of Compensation Committee
















                                      -6-