SecProbe.io

December 9, 2011
 Via E-mail

Richard Rutkowski Chief Executive Officer ClearSign Combustion Corporation 12870 Interurban Avenue South Seattle, Washington 98168
Re: ClearSign Combustion Corporation
 Registration Statement on Form S-1
Filed November 14, 2011
  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.
 Public Offering Prospectus Cover Page

 1. We note your cover page includes the “subj ect to completion” legend but does not
indicate that a price range will be included in the event a preliminary prospectus is
circulated.  Please confirm that any prelimin ary prospectus you circulate will include all
non-Rule 430A information.  This includes th e price range and related information based
on a bona fide  estimate of the public offering pr ice within that range, and other
information that was left blank throughout th e document.  Also note that we may have
additional comments after you file this information.
2. Here and elsewhere in your document, as appr opriate, please includ e a brief description
of the concurrent selling stoc kholder offering.  Also disclose how the price of the shares
being offered by the selling stockholders diffe rs from the price of the shares you are
offering in this underwritten offering.

Richard Rutkowski ClearSign Combustion Corporation December 9, 2011 Page 2

3. Please revise the cover page to disclose your relationship with MDB Capital Group and
its affiliates.  Please also revise to disclose on the c over page the dollar amount and
percentage of the net proceeds of the offering th at will be paid to or for the benefit of the
underwriters and/or their affiliates.
Graphics, page i and back cover

4. We note the significant amount of text in your graphics and that much of that text is already
contained elsewhere in your prospectus.  You may use text on the inside cover page only to
the extent necessary to explain briefly the visuals in the presentation.  Please revise
accordingly.

5. The use of the photographs in your graphics is  not appropriate for your level of product
development.  While we note that you do not have revenues at this time, readers may be
left with the impression that products you are selling or trying  to sell are being shown in
the photographs.  Please revise accordingly.
Special Note Regarding Forwar d Looking Statements, page iii

 6. Please move this section to a later section of your prospectus  rather than prior to the
summary and the risk factors.
About ClearSign Combusti on Corporation, page 1

 7. We note your brief summary.  The summary s hould be a balanced presentation of your
business that presents the ke y aspects of the offering and your business.  Please expand
your disclosure here and elsewhere as a ppropriate to explain the status of your
technology and that you have not yet de veloped products based on your technology.
Also highlight that your financ ial statements have been pr epared on the basis that you
will continue as a going concern and that there is substantial doubt about your ability to
continue as a going concern.  Please quantify your net losses in  the past two fiscal years
and any interim periods, and indicate the amount of your accumulated deficit.

8. We note your statements in the first para graph that you “design, develop and market”
technologies.   As you have not yet introdu ced a product, please remove “market” from
this list.
 Our Industry, page 1

 9. We note the statements in this paragraph about  the “trillions” in cap ital assets and that
operators invest “billions” in  installing, maintaining and upgr ading these systems.  We
further note your disclosure in the “Our Target  Markets” section on pa ge 3.  It is unclear
why you have implied that these markets are yo ur addressable markets, as it appears your
potential products would only be applicable to a subset of these markets.  Please revise or

Richard Rutkowski ClearSign Combustion Corporation December 9, 2011 Page 3

 advise.  Also, please provide us independent  objective support for the statement on page
1 regarding world total energy consumption and on page 3 regarding the size of your
addressable market.
Our Proprietary Technology, page 2

 10. We note your statement that you believe your  platform “may increase energy, and
improve fuel flexibility and environmental pe rformance for most types of industrial and
commercial combustion systems.”  Please revise  your disclosure to clearly identify the
specific basis for your belief, and clarify the products or  technology against which you
are comparing your platform. If you have not  yet developed a product that has been
objectively tested with statistic ally significant results, it is unclear why you believe it is
appropriate to make these claims in your document.
Intellectual Property, page 3

 11. Please revise your disclosure so that i nvestors can understand the nature of your
intellectual property.  In this regard, please clarify the terms “prior art” and “reduction to
practice” by using concrete, every day terms.  Also, your disclosure here should be
balanced in describing the limitations of your current intellect ual property and its
protections.  Please revise accordingly.

Prototypes and Experime ntal Data, page 3

 12. We note your vague disclosure about having “designed and/or built several prototype
systems” and that you have conducted “numer ous” and “repeated” experiments.  Please
expand and revise your disclo sure to provide more spec ific disclosure about your
prototypes and experimental data.  Also avoid marketing jargon such as “will be a rapid path to commercialization and a robust product pipeline.”

Partners, page 4

 13. Please disclose the extent of your current agr eements with potential partners. If you have
not commenced seeking out such partners, please clearly state that fact here.

The Offering, page 5

 14. Tell us where you have provided disclosure pu rsuant to Item 505(a) of Regulation S-K.

15. We note you state the proceeds are to be used  for “working capital and general corporate
purposes,” yet on page 36 you state that th e “proceeds received from this offering are
expected to be used in our efforts related to  research and developm ent, protection of our
intellectual property, and expl oration of market opportunities.”   Please reconcile and
revise as necessary to state clearly  the intended uses of proceeds.

Richard Rutkowski ClearSign Combustion Corporation December 9, 2011 Page 4

 System Results, page 21

 16. Please expand your disclosure to identify the basis for the results in the photographs
provided in your prospectus.  For example, if these photographs were taken during the
course of your experiments, please disclo se how many experiments were run and how
often the observed results occurred.
17. We note your disclosure in the first paragra ph on page 24.  It is unclear why you believe
it is appropriate to include the disclosure in  the first paragraph on page 24 regarding the
“favorable” response of “subject matter expert s” and “positive resu lts” of potential
customers to your “selective pr esentations” of the data obt ained from the experiments
you conducted without providing significant addi tional disclosure a bout the nature and
scope of the experiments conducted, the pres entations given, how you found the subject
matter experts and the criteria you used to id entify them as such, and other important
contextual information.  Pl ease advise or revise.
  Research and Development Plan, page 24

 18. We note your discussion of wher e your R&D efforts are to be  focused in the future.
Please expand your disclosure to describe in details the steps required to complete the
sequence described in the four  bullet points and the anticipa ted costs associated with
completing each bullet point.

Product Roadmap and Path to Commercialization, page 25

 19. We note you describe your technology in mark eting terms, such as your statements that
your technology “easily and cost-effectively”  combines with pollution control and
promises “to improve the reliability of existing systems while lowering operating costs and energy use.”  Please revise to av oid the use of marketing terms.

Competition and Barriers to Entry, page 36

 20. We note you have only described the shortc omings of your competitors’ offerings.
Please expand to describe the benefits your competitors’ products compared to your
technology.   Also, please expand your disclosure  to disclose that your competitors have
greater financial resources and market share than you do.

Competitive Advantage, page 36

 21. Please provide independent, objective suppor t for your statements in this section
regarding the advantages of your technology.  For example, we note your statements that
your technology has the potential  to deliver “discernable a nd measurable advantages as
compared to currently available technology.”  We also note your stat ements in the bullet
points on page 37.

Richard Rutkowski ClearSign Combustion Corporation December 9, 2011 Page 5

 Management’s Discussion and Analysis of Financ ial Condition and Results of Operations, page
40
 Liquidity and Capital Resources, page 42

 22. We note that you are a development stage company and there is substantial doubt
regarding your ability to continue as a going concern. Please expand to describe your
plan of operations, including the expected  timeframe and funding requirements to
develop your technology and products a nd the expected source of your funding
requirements. Please also disclose the dollar amount of financing you believe is required
to continue your business over the next twelve  months.  For further guidance, refer to
Section IV.A. of Securities Act Releas e 33-8350 “Commission Guidance Regarding
Management's Discussion and Analysis of Financial Conditio n and Results of
Operations.”
Technical Advisors, page 48

 23. Please expand your description of the role of the technical advisors for whom you
provide biographical information here.  Also  expand your discussion of the compensation
of these advisors, including cash, stock, and/or  options issued to date, and clarify how
compensation is determined.  Indicate whet her you have any agreements with these
advisors, including compensation agreements.
 Current and Future Compensation Practices, page 51

 24. While you state that currentl y, your compensation program is only for cash, we note you
state that during 2011 you “implemented a co mpensation program” of base salary and
stock.  Please expand your disclosure to de scribe this program in  detail, including the
compensation to be paid and how that compensation was determined.
25. We note you state in setting compensation, you look at salaries paid to others in business
similar to yours.  Please identify those busin esses and tell how the compensation you paid
compares to the other bu sinesses’ compensation.
 26. We note you state that you may pay bonuses in the future for achievement of agreed upon
targets.  Please tell us whether those target s have been set and, if so, why you have not
disclosed them.
 Capitalization, page 64

 27. Please remove cash and cash equivalents from  the Capitalization ta ble on page 64 since
this is not a component of capitalization.

Richard Rutkowski ClearSign Combustion Corporation December 9, 2011 Page 6

 Unaudited Financial Statements for the Quarter Ended June 30, 2011

 28. Please update the financial statements as required by Article 8-08 of Regulation S-X.

Note 4. Stockholder’s Equity/(Deficit), page F-17

 29. We note that you issued 109,091 and 101,818 shares of common stock as part of issuance
costs.  Please clarify where this is reflected  in the Statement of Changes in Stockholder’s
Equity/(Deficit).
Selling Security Holder Prospectus Cover, page II-2

 30. Note that Schedule A, paragraph 16 of th e Securities Act and Item 501(b)(3) of
Regulation S-K require that you disclose the pr ice at which the securities will be sold.
Given the lack of an established market for your securities, a statement that selling
stockholders will sell “at prevailing market prices” is insufficient to satisfy your
disclosure obligation.  Please disclose the fixe d price you intend to sell  the shares listed in
this prospectus.  We will not obj ect if you disclose that the se curities will be sold at the
disclosed fixed price until your shares ar e listed on the NASDAQ and thereafter at
prevailing market prices or pr ivately negotiated prices.

Selling Security Holder Table, page II-6

 31. Please tell us whether any of the selling shar eholders are broker-dealers or affiliates of
broker-dealers. A selling stockholder who is an affiliate of a broker-dealer must be
identified in the prospectus as an underwriter unless the prospectus stat es, if true, that: the
selling shareholder purchased the shares being registered for re sale in the ordinary course
of business, and at the time of the purchase, the selling shareholder had no agreements or
understandings, directly or indi rectly, with any person to dist ribute the securities. Please
revise as appropriate.
Exhibits

 32. Please file all exhibits with your next amen dment.  We may have further comment after
reviewing those exhibits.
 33. To the extent there is a delay in requesting e ffectiveness of your registration statement, or
there is any change, other than typographical, made to the financial statements, or there
have been intervening events  since the prior filing that are material to the company,
please provide a currently dated and signed consent from your independent accountants
with the next amendment.

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

Richard Rutkowski ClearSign Combustion Corporation December 9, 2011 Page 7

 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