SecProbe.io

February 17, 2012
 Via E-mail

Richard Rutkowski Chief Executive Officer ClearSign Combustion Corporation 12870 Interurban Avenue South Seattle, Washington 98168
Re: ClearSign Combustion Corporation
 Amendment No. 2 to Registra tion Statement on Form S-1
Filed February 7, 2012
  File No. 333-177946

Dear Mr. Rutkowski:

We have reviewed your registration statem ent and have the following comments.  In
some of our comments, we may ask you to provi de us with information so we may better
understand your disclosure.
 Please respond to this letter by amending your registration statement and providing the
requested information.  If you do not believe  our comments apply to your facts and
circumstances or do not believe an amendment is appropriate, please tell us why in your
response.
 After reviewing any amendment to your re gistration statement and the information you
provide in response to these comments , we may have additional comments.
 Prospectus Cover Page

 1. We note your response to prior comment 1 that once the price or price range is
determined you will file a prospectus supplemen t that provides this information and that
you do not have any price ranges included at th is time.  Please note that paragraph 16 of
Schedule A of the Securities Act and Regula tion S-K Item 501(b)(3) require that you
disclose the price at which the securities wi ll be sold.  Please revi se the underwritten
offering prospectus to include a price range  and all non-Rule 430A information prior to
circulating any preliminary prospectus.  With respect to the selling shareholder
prospectus, given the lack of an established market for your securitie s, please note that a
statement that selling shareholders will sell “a t market prices” is insufficient to satisfy
your disclosure obligation.  Th erefore, please disclose th e fixed price at which the
securities will be sold.  We will not object if you also elect to disclose that the selling
shareholders will sell at the fixed price until  your shares are quoted on the OTC Bulletin
Board and thereafter at prevailing market prices or privately negotiated prices.

Richard Rutkowski ClearSign Combustion Corporation February 17, 2012 Page 2

Research and Development Plan, page 25

 2. We note you revised the disclosure on page 25 in response to prior comment 5.  Please
revise to clarify the costs associated with completing each step in the development plan
rather than only the portion of the offering proceeds that will be applied to each step.

We urge all persons who are responsible for th e accuracy and adequacy of the disclosure
in the filing to be certain that the filing incl udes the information the Securities Act of 1933 and
all applicable Securities Act rules require.  Since the company and its management are in
possession of all facts relating to a company’s disc losure, they are responsible for the accuracy
and adequacy of the disclosures they have made.
Notwithstanding our comments, in the event you request acceleration of  the effective date
of the pending registration statement please pr ovide a written statement from the company
acknowledging that:
 should the Commission or the staff, acting purs uant to delegated authority, declare the
filing effective, it does not foreclose the Co mmission from taking any action with respect
to the filing;

 the action of the Commission or the staff, acting pursuant to delegated authority, in
declaring the filing effective, does not relieve the company from its full responsibility for
the adequacy and accuracy of the disclosure in the filing; and

 the company may not assert staff comments a nd the declaration of effectiveness as a
defense in any proceeding initiated by the Commission or any person under the federal
securities laws of the United States.

Please refer to Rules 460 and 461 regarding re quests for acceleration.  We will consider a
written request for acceleration of  the effective date of the regi stration statement as confirmation
of the fact that those reques ting acceleration are aware of thei r respective responsibilities under
the Securities Act of 1933 and the Securities Excha nge Act of 1934 as they relate to the proposed
public offering of the securities specified in th e above registration stat ement.  Please allow
adequate time for us to review any amendment prior to the requested effective date of the
registration statement.

Richard Rutkowski ClearSign Combustion Corporation February 17, 2012 Page 3

 You may contact Praveen Kart holy at 202-551-3778 or Brian Cascio, Accounting Branch
Chief, at 202-551-3676 if you have questions rega rding comments on the financial statements
and related matters.  Please contact Jay Mumf ord at 202-551-3637 or Mary Beth Breslin at 202-
551-3625 with any other questions.

Sincerely,

/s/ Mary Beth Breslin for

        A m a n d a  R a v i t z          A s s i s t a n t  D i r e c t o r   cc (via e-mail): Kevin Friedmann