Claymore Securities, Inc. 2455 Corporate West Drive Lisle, Illinois 60532 December 7, 2009 Securities and Exchange Commission 100 F Street, N.E. Washington, DC 20549 Re: Claymore Securities Defined Portfolios, Series 648 File No. 333-162646 Ladies/Gentlemen: The undersigned, Claymore Securities Defined Portfolios, Series 648 (the "Trust"), by Claymore Securities, Inc., as the sponsor and depositor of the Trust and of the units covered by the subject Registration Statement, pursuant to the provisions of Rule 461 of the General Rules and Regulations of the Securities and Exchange Commission under the Securities Act of 1933, hereby respectfully requests that the Securities and Exchange Commission consent to the filing of the amendment to the Registration Statement and grant acceleration of the effectiveness of said Registration Statement, as amended, so that the same may become effective as early as practicable on December 9, 2009 or as soon thereafter as possible. Very truly yours, Claymore Securities Defined Portfolios, Series 648 By: Claymore Securities, Inc. By: /S/ Kevin Robinson Kevin Robinson Senior Managing Director, General Counsel and Secretary