Filed electronically with the Securities and Exchange Commission
                            on November 30, 2007

                                                               File No. 2-36238
                                                               File No. 811-2021

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D. C. 20549

                                    FORM N-1A


                   REGISTRATION STATEMENT UNDER THE SECURITIES
                                   ACT OF 1933
                         Pre-Effective Amendment No. ___
                         Post-Effective Amendment No. 99
                                     and/or
                        REGISTRATION STATEMENT UNDER THE
                         INVESTMENT COMPANY ACT OF 1940
                                Amendment No. 83
                                              --

                              DWS SECURITIES TRUST
                              --------------------
               (Exact Name of Registrant as Specified in Charter)

                 Two International Place, Boston, MA 02110-4103
                 ----------------------------------------------
               (Address of Principal Executive Offices) (Zip Code)

       Registrant's Telephone Number, including Area Code: (617) 295-2572
                                                           --------------


                                  John Millette
                              DWS SECURITIES TRUST
                    Two International Place, Boston, MA 02110
                     (Name and Address of Agent for Service)

It is proposed that this filing will become effective (check appropriate box):

[_]    Immediately upon filing pursuant to paragraph (b)
[X]    On December 1, 2007 pursuant to paragraph (b)
[_]    60 days after filing pursuant to paragraph (a)(1)
[_]    On ______________ pursuant to paragraph (a)(1)
[_]    75 days after filing pursuant to paragraph (a)(2)
[_]    On ______________ pursuant to paragraph (a)(2)
[_]    On ______________ pursuant to paragraph (a)(3) of Rule 485

       If appropriate, check the following box:
[_]    This post-effective amendment designates a new effective date for a
       previously filed post-effective amendment


<PAGE>


                                EXPLANATORY NOTE
                                ----------------

This Post-Effective Amendment No. 99 to the Registration Statement on form N-1A
(File No. 811-02021) is being filed in order to revise the Part C of the
Registration Statement and to include Exhibits 23(f)(1) and 23(f)(2) which were
not included with Post-Effective Amendment No. 98 to the Registration Statement
filed on November 28, 2007. The provisions of the Prospectuses (Part A) and
Statements of Additional Information (Part B) of Post-Effective Amendment No. 98
to the Registration Statement on Form N-1A, File No. 811-02021, filed on
November 28, 2007 are incorporated by reference in their entirety

This post-effective amendment is not intended to update or amend any other
prospectuses or statements of additional information of the registrant's other
series or classes.

<PAGE>


<TABLE>
<CAPTION>

                                        PART C. OTHER INFORMATION

Item 23.            Exhibits
--------            --------

<S>                 <C>      <C>      <C>
                    (a)      (1)      Amended and Restated Declaration of Trust dated August 31, 2006 is
                                      incorporated by reference to Post-Effective Amendment No. 93 to the
                                      Registration Statement.

                             (2)      Amended and Restated Designation of Series and Classes of Shares of
                                      Beneficial Interest with respect to DWS Climate Change Fund is
                                      incorporated by reference to Post-Effective Amendment No. 96 to the
                                      Registration Statement.

                    (b)               By-Laws dated June 27, 2006 is incorporated by reference to
                                      Post-Effective Amendment No. 93 to the Registration Statement.

                    (c)               Inapplicable.

                    (d)      (1)      Amended and Restated Investment Management Agreement, dated June 1,
                                      2006 between the Registrant and Deutsche Investment Management
                                      Americas Inc. is incorporated by reference to Post-Effective
                                      Amendment No. 96 to the Registration Statement.

                             (2)      Sub-advisory Agreement dated September 6, 2007 between the
                                      Registrant, Deutsche Investment Management Americas Inc. and
                                      Deutsche Asset Management International GmbH is incorporated by
                                      reference to Post-Effective Amendment No. 97 to the Registration
                                      Statement.

                    (e)      (1)      Underwriting Agreement between the Registrant and Scudder Investor
                                      Services, Inc. dated April 5, 2002, is incorporated by reference to
                                      Post-Effective Amendment No. 80 to the Registration Statement.

                             (2)      Underwriting and Distribution Services Agreement between the
                                      Registrant and Scudder Distributors, Inc. dated April 5, 2002, is
                                      incorporated by reference to Post-Effective Amendment No. 80 to the
                                      Registration Statement.

                             (3)      Underwriting Services Agreement between the Registrant and Scudder
                                      Distributors, Inc. dated September 30, 2002, is incorporated by
                                      reference to Post-Effective Amendment No. 80 to the Registration
                                      Statement.

                    (f)      (1)      Form of Retirement Agreement between the Registrant and each of
                                      Martin J. Gruber, Graham E. Jones and Carl W. Vogt dated November
                                      14, 2007 (filed herein).

                             (2)      Indemnification and Reimbursement Agreement between the Registrant
                                      and DIMA dated November 14, 2007 (filed herein).

<PAGE>

                    (g)      (1)      Custodian Agreement between the Registrant and State Street Bank
                                      and Trust Company, dated April 13, 2004, is incorporated by
                                      reference to Post-Effective Amendment No. 87 to the Registration
                                      Statement.

                             (2)      Master Custodian Agreement between the Registrant and Brown
                                      Brothers Harriman & Co., dated February 1, 2007, is incorporated by
                                      reference to Post-Effective Amendment No. 96 to the Registration
                                      Statement.


                    (h)      (1)      Agency Agreement between the Registrant and DWS Scudder Investment
                                      Services Company, dated April 1, 2007 is incorporated by reference
                                      to Post-Effective Amendment No. 96 to the Registration Statement.

                             (2)      Shareholder Services Agreement between the Registrant and Scudder
                                      Distributors, Inc. dated April 5, 2002, is incorporated by
                                      reference to Post-Effective Amendment No. 80 to the Registration
                                      Statement.

                             (3)      Letter of Indemnity to the Scudder Funds dated October 13, 2004 is
                                      incorporated by reference to Post-Effective Amendment No. 90 to the
                                      Registration Statement.

                             (4)      Indemnification for service as an Independent Trustee of a
                                      Liquidating Fund dated October 13, 2004 is incorporated by
                                      reference to Post-Effective Amendment No. 90 to the Registration
                                      Statement.

                             (5)      Letter of Indemnity to the Independent Trustees dated October 13,
                                      2004 is incorporated by reference to Post-Effective Amendment No.
                                      90 to the Registration Statement.

                             (6)      Administrative Services Agreement between the Registrant and
                                      Deutsche Investment Management Americas Inc. is incorporated by
                                      reference to Post-Effective Amendment No. 96 to the Registration
                                      Statement.

                             (7)      Form of Mutual Fund Rule 22c-2 Information Sharing Agreement
                                      between the Registrant and DWS Scudder Distributors Inc. is
                                      incorporated by reference to Post-Effective Amendment No. 96 to the
                                      Registration Statement.

                    (i)               Legal Opinion and Consent of Counsel is incorporated by reference
                                      to Post-Effective Amendment No. 81 and No. 96 to the Registration
                                      Statement.

                    (j)               Consent of Independent Registered Public Accounting Firm is incorporated
                                      by reference to Post-Effective Amendment No. 98 to the Registration
                                      Statement.

                    (k)               Inapplicable.
                                      Registration Statement.

                                       2
<PAGE>


                    (l)               Inapplicable.

                    (m)      (1)      Rule 12b-1 Plan between the Registrant, on behalf of Scudder Health
                                      Care Fund (Class A,B and C shares), dated November 13, 2000, is
                                      incorporated by reference to Post-Effective Amendment No. 76 to the

                             (2)      Rule 12b-1 Plan between the Registrant on behalf of DWS Climate
                                      Change Fund (Class A shares), dated September 4, 2007 is
                                      incorporated by reference to Post-Effective Amendment No. 96 to the
                                      Registration Statement.

                             (3)      Rule 12b-1 Plan between the Registrant on behalf of DWS Climate
                                      Change Fund (Class C shares), dated September 4, 2007 is
                                      incorporated by reference to Post-Effective Amendment No. 96 to the
                                      Registration Statement.

                    (n)               Amended and Restated Multi-Distribution System Plan
                                      (Rule 18f-3), dated May 15, 2002 is incorporated by reference to
                                      Post-Effective Amendment No. 81 to the Registration Statement.

                    (p)      (1)      Consolidated Fund Code of Ethics dated March 14, 2006 is
                                      incorporated by reference to Post-Effective Amendment No. 93 to the
                                      Registration Statement.

                             (2)      Code of Ethics for Deutsche Asset Management - U.S., dated January
                                      1, 2007, incorporated by reference to Post-Effective Amendment No.
                                      95 to the Registration Statement.

                             (3)      Code of Ethics for Deutsche Asset Management International GmbH is
                                      incorporated by reference to Post-Effective Amendment No. 96 to the
                                      Registration Statement.

                    (q)               Power of attorney is incorporated by reference to Post-Effective
                                      Amendment No. 93 to the Registration Statement.
</TABLE>

Item 24.          Persons Controlled by or under Common Control with Registrant
--------          -------------------------------------------------------------

                  None

Item 25.          Indemnification
--------          ---------------

                  Article IV of the Registrant's Agreement and Declaration of
                  Trust (Exhibit (a)) hereto, which is incorporated herein by
                  reference) provides in effect that the Registrant will
                  indemnify its officers and trustees under certain
                  circumstances. However, in accordance with Section 17(h) and
                  17(i) of the Investment Company Act of 1940 and its own terms,
                  said Article of the Agreement and Declaration of Trust does
                  not protect any person against any liability to the Registrant
                  or its shareholders to which such Trustee would otherwise be
                  subject by reason of willful misfeasance, bad faith, gross
                  negligence, or reckless disregard of the duties involved in
                  the conduct of his or her office.

                  The Registrant has purchased insurance policies insuring its
                  officers and trustees against certain liabilities which such
                  officers and trustees may incur while acting in

                                       3
<PAGE>

                  such capacities and providing reimbursement to the Registrant
                  for sums which it may be permitted or required to pay to its
                  officers and trustees by way of indemnification against such
                  liabilities, subject to certain deductibles.

                  On April 5, 2002, Zurich Scudder Investments, Inc.
                  ("Scudder"), the investment adviser, now known as Deutsche
                  Investment Management Americas Inc., was acquired by Deutsche
                  Bank AG, not including certain U.K. Operations (the
                  "Transaction"). In connection with the Trustees' evaluation of
                  the Transaction, Deutsche Bank agreed to indemnify, defend and
                  hold harmless Registrant and the trustees who were not
                  "interested persons" of Scudder, Deutsche Bank or Registrant
                  (the "Independent Trustees") for and against any liability and
                  claims and expenses based upon or arising from, whether in
                  whole or in part, or directly or indirectly, any untrue
                  statement or alleged untrue statement of a material fact made
                  to the Independent Trustees by Deutsche Bank in connection
                  with the Independent Trustees' consideration of the
                  Transaction, or any omission or alleged omission of a material
                  fact necessary in order to make statements made, in light of
                  the circumstances under which they were made, not misleading.

                  Deutsche Investment Management Americas Inc. (hereafter,
                  "DIMA"), the investment advisor, has agreed, subject to
                  applicable law and regulation, to indemnify and hold harmless
                  the Registrant against any loss, damage, liability and
                  expense, including, without limitation, the advancement and
                  payment, as incurred, of reasonable fees and expenses of
                  counsel (including counsel to the Registrant and counsel to
                  the Independent Trustees) and consultants, whether retained by
                  the Registrant or the Independent Trustees, and other
                  customary costs and expenses incurred by the Registrant in
                  connection with any litigation or regulatory action related to
                  possible improper market timing or other improper trading
                  activity or possible improper marketing and sales activity in
                  the Registrant ("Private Litigation and Enforcement Actions").
                  In the event that this indemnification is unavailable to the
                  Registrant for any reason, then DIMA has agreed to contribute
                  to the amount paid or payable by the Registrant as a result of
                  any loss, damage, liability or expense in such proportion as
                  is appropriate to reflect the relative fault of DIMA and the
                  Registrant with respect to the matters which resulted in such
                  loss, damage, liability or expense, as well as any other
                  relevant equitable considerations; provided, that if no final
                  determination is made in such action or proceeding as to the
                  relative fault of DIMA and the Registrant, then DIMA shall pay
                  the entire amount of such loss, damage, liability or expense.

                  In recognition of its undertaking to indemnify the Registrant,
                  and in light of the rebuttable presumption generally afforded
                  to non-interested board members of an investment company that
                  they have not engaged in disabling conduct, DIMA has also
                  agreed, subject to applicable law and regulation, to indemnify
                  and hold harmless each of the Independent Trustees against any
                  and all loss, damage, liability and expense, including without
                  limitation the advancement and payment as incurred of
                  reasonable fees and expenses of counsel and consultants, and
                  other customary costs and expenses incurred by the Independent
                  Trustees, arising from the matters alleged in any Private
                  Litigation and Enforcement Actions or matters arising from or
                  similar in subject matter to the matters alleged in the
                  Private Litigation and Enforcement Actions (collectively,
                  "Covered Matters"), including without limitation:

                  1.       all reasonable legal and other expenses incurred by
                           the Independent Trustees in connection with the
                           Private Litigation and Enforcement Actions, and any
                           actions that may be threatened or commenced in the
                           future by any person (including any governmental
                           authority), arising from or similar to the matters
                           alleged in the Private Litigation and Enforcement

                                       4
<PAGE>


                           Actions, including without limitation expenses
                           related to the defense of, service as a witness in,
                           or monitoring of such proceedings or actions;

                  2.       all liabilities and reasonable legal and other
                           expenses incurred by any Independent Trustee in
                           connection with any judgment resulting from, or
                           settlement of, any such proceeding, action or matter;

                  3.       any loss or reasonable legal and other expenses
                           incurred by any Independent Trustee as a result of
                           the denial of, or dispute about, any insurance claim
                           under, or actual or purported rescission or
                           termination of, any policy of insurance arranged by
                           DIMA (or by a representative of DIMA acting as such,
                           acting as a representative of the Registrant or of
                           the Independent Trustees or acting otherwise) for the
                           benefit of the Independent Trustee, to the extent
                           that such denial, dispute or rescission is based in
                           whole or in part upon any alleged misrepresentation
                           made in the application for such policy or any other
                           alleged improper conduct on the part of DIMA, any of
                           its corporate affiliates, or any of their directors,
                           officers or employees;

                  4.       any loss or reasonable legal and other expenses
                           incurred by any Independent Trustee, whether or not
                           such loss or expense is incurred with respect to a
                           Covered Matter, which is otherwise covered under the
                           terms of any specified policy of insurance, but for
                           which the Independent Trustee is unable to obtain
                           advancement of expenses or indemnification under that
                           policy of insurance, due to the exhaustion of policy
                           limits which is due in whole or in part to DIMA or
                           any affiliate thereof having received advancement of
                           expenses or indemnification under that policy for or
                           with respect to any Covered Matter; provided, that
                           the total amount that DIMA will be obligated to pay
                           under this provision for all loss or expense shall
                           not exceed the amount that DIMA and any of its
                           affiliates actually receive under that policy of
                           insurance for or with respect to any and all Covered
                           Matters; and

                  5.       all liabilities and reasonable legal and other
                           expenses incurred by any Independent Trustee in
                           connection with any proceeding or action to enforce
                           his or her rights under the agreement, unless DIMA
                           prevails on the merits of any such dispute in a
                           final, nonappealable court order.

                  DIMA is not required to pay costs or expenses or provide
                  indemnification to or for any individual Independent Trustee
                  (i) with respect to any particular proceeding or action as to
                  which the Board of the Registrant has determined that such
                  Independent Trustee ultimately would not be entitled to
                  indemnification with respect thereto, or (ii) for any
                  liability of the Independent Trustee to the Registrant or its
                  shareholders to which such Independent Trustee would otherwise
                  be subject by reason of willful misfeasance, bad faith, gross
                  negligence, or reckless disregard of the Independent Trustee's
                  duties as a Trustee of the Registrant as determined in a final
                  adjudication in such proceeding or action. In addition, to the
                  extent that DIMA has paid costs or expenses under the
                  agreement to any individual Independent Trustee with respect
                  to a particular proceeding or action, and there is a final
                  adjudication in such proceeding or action of the Independent
                  Trustee's liability to the Registrant or its shareholders by
                  reason of willful misfeasance, bad faith, gross negligence, or
                  reckless disregard of the Independent Trustee's duties as a
                  Trustee of the Registrant, such Independent Trustee has
                  undertaken to repay such costs or expenses to DIMA.

                  On November 14, 2007, the Registrant and DIMA entered into an
                  agreement that provides certain retiring Non-interested
                  Trustees certain assurances regarding continuation of
                  insurance and indemnification rights. More specifically, the
                  agreement


                                       5
<PAGE>

                  provides that the Registrant shall take all actions reasonably
                  necessary to assure that the retirement of certain
                  Non-interested Trustees and/or the election or appointment of
                  members of the consolidated Board shall not reduce or impair
                  any rights of those Non-interested Trustees to
                  indemnification, defense, advancement of expenses, or other
                  rights, for or with respect to actual or threatened claims,
                  liability, or expense that those Non-interested Trustees may
                  incur or suffer arising from or with respect to those
                  Non-interested Trustees' service in such capacity, except to
                  the extent that the consolidated Board determines in the
                  exercise of its duties to modify the rights of all Board
                  members, past and present, without distinction. It is
                  understood that any such modification of rights shall not,
                  without the written consent of the Non-interested Trustees,
                  serve to modify any contractual rights that the Non-interested
                  Trustees may have under any agreement to which the
                  Non-interested Trustees and the Registrant are parties.

                  For the six-year period following the election or appointment
                  of members of the consolidated Board, the Registrant currently
                  expect to maintain, D&O/E&O Insurance and IDL Insurance that
                  is substantially equivalent in scope to the current coverage,
                  and in amounts providing aggregate coverage with respect to
                  the Registrant and all funds overseen by the consolidated
                  Board of at least $100 million for D&O/E&O Insurance and at
                  least $25 million for IDL Insurance; subject however to the
                  right of the consolidated Board in the exercise of its duties
                  to determine that a lower level of insurance coverage is in
                  the best interests of the Registrant provided that any such
                  reduction in coverage apply equally to their present and
                  former Trustees.

                  Pursuant to the agreement, DIMA has agreed that the retirement
                  of the Non-interested Trustees under the terms of the
                  retirement agreements shall in no way affect or diminish the
                  contractual rights of indemnification that the Non-interested
                  Trustees may have under any agreement of indemnification
                  between an Non-interested Trustees and DIMA, including without
                  limitation agreements of indemnification currently in effect
                  with respect to matters related to market timing and matters
                  related to merged or liquidated funds. Upon request made by
                  any Non-interested Trustees, DIMA has agreed to execute a
                  separate instrument confirming the existence and continuation
                  of any such agreement of indemnification.

                  In addition, pursuant to the agreement, in the event that the
                  consolidated Board determines to reduce insurance coverage
                  below the minimum levels stated above, then DIMA at its
                  expense will purchase excess insurance coverage for the
                  benefit of the Non-interested Trustees sufficient to maintain
                  such minimum coverage levels in place for the duration of the
                  period specified in the retirement agreements, provided that
                  in the event that such excess coverage is not available in the
                  marketplace on commercially reasonable terms from a
                  conventional third-party insurer, DIMA (or an affiliate of
                  DIMA) may, at DIMA's discretion and in lieu of purchasing such
                  excess insurance coverage, elect instead to provide the
                  Non-interested Trustees substantially equivalent protection in
                  the form of a written indemnity or financial guaranty
                  reasonably acceptable to each such Non-interested Trustees.

Item 26.          Business and Other Connections of Investment Advisor
--------          ----------------------------------------------------

                  During the last two fiscal years, no director or officer of
                  Deutsche Investment Management Americas Inc., the investment
                  advisor, has engaged in any other business, profession,
                  vocation or employment of a substantial nature other than that
                  of the business of investment management and, through
                  affiliates, investment banking.

                                       6
<PAGE>

Item 27.          Principal Underwriters
--------          ----------------------

                  (a)

                  DWS Scudder Distributors, Inc. acts as principal underwriter
                  of the Registrant's shares and acts as principal underwriter
                  for registered open-end management investment companies other
                  funds managed by Deutsche Investment Management Americas Inc.

                  (b)

                  Information on the officers and directors of DWS Scudder
                  Distributors, Inc., principal underwriter for the Registrant,
                  is set forth below. The principal business address is 222
                  South Riverside Plaza, Chicago, Illinois 60606.

<TABLE>
<CAPTION>

                      (1)                             (2)                                  (3)
          DWS Scudder Distributors,
          Inc.
          Name and Principal             Positions and Offices with               Positions and
          Business Address               DWS Scudder Distributors, Inc.           Offices with Registrant
          ----------------               ------------------------------           -----------------------

<S>      <C>                            <C>                                       <C>
         Philipp Hensler                Director, Chairman of the Board and CEO   None
         345 Park Avenue
         New York, NY 10154

         Michael Colon                  Director and Chief Operating Officer      None
         345 Park Avenue
         New York, NY 10154

         Thomas Winnick                 Director and President                    None
         345 Park Avenue
         New York, NY 10154

         Cliff Goldstein                Chief Financial Officer and Treasurer     None
         60 Wall Street
         New York, NY 10005

         Robert Froehlich               Vice President                            None
         222 South Riverside Plaza
         Chicago, IL 60606

         Paul Schubert                  Vice President                            Chief Financial Officer
         345 Park Avenue                                                          and Treasurer
         New York, NY 10154

         Mark Perrelli                  Vice President                            None
         222 South Riverside Plaza
         Chicago, IL 60606

         Donna White                    Chief Compliance Officer                  None
         345 Park Avenue
         New York, NY 10154


                                       7
<PAGE>


                      (1)                             (2)                                  (3)
          DWS Scudder Distributors,
          Inc.
          Name and Principal               Positions and Offices with                 Positions and
          Business Address               DWS Scudder Distributors, Inc.           Offices with Registrant
          ----------------               ------------------------------           -----------------------

         Jason Vazquez                  Vice President and AML Compliance         Anti-Money Laundering
         345 Park Avenue                Officer                                   Compliance Officer
         New York, NY 10154

         Caroline Pearson               Secretary                                 Assistant Secretary
         Two International Place
         Boston, MA 02110

         Philip J. Collora              Assistant Secretary                       None
         222 South Riverside Plaza
         Chicago, IL 60606

         Anjie LaRocca                  Assistant Secretary                       None
         345 Park Avenue
         New York, NY 10154
</TABLE>

         (c)      Not applicable

Item 28.          Location of Accounts and Records
--------          --------------------------------

                  Certain accounts, books and other documents required to be
                  maintained by Section 31(a) of the 1940 Act and the Rules
                  promulgated thereunder are maintained by Deutsche Investment
                  Management Americas Inc., Two International Place, Boston, MA
                  02110-4103. Records relating to the duties of the Registrant's
                  custodian are maintained by State Street Bank and Trust
                  Company, Heritage Drive, North Quincy, Massachusetts. Records
                  relating to the duties of the Registrant's transfer agent are
                  maintained by DWS Scudder Service Corporation, Two
                  International Place, Boston, Massachusetts.

Item 29.          Management Services
--------          -------------------

                  Inapplicable.

Item 30.          Undertakings
--------          ------------

                  Inapplicable.



                                       8
<PAGE>

                                   SIGNATURES
                                   ----------

      Pursuant to the requirements of the Securities Act of 1933 and the
Investment Company Act of 1940, the Registrant certifies that it meets all of
the requirements for effectiveness of this Registration Statement pursuant to
Rule 485(b) under the Securities Act of 1933 and has duly caused this amendment
to its Registration Statement to be signed on its behalf by the undersigned,
thereto duly authorized, in the City of New York and the State of New York on
the 19th day of November 2007.

                                          DWS SECURITIES TRUST

                                          By:  /s/ Michael G. Clark
                                               --------------------
                                                  Michael G. Clark
                                                  President

      Pursuant to the requirements of the Securities Act of 1933, this
Post-Effective Amendment to its Registration Statement has been signed below by
the following persons in the capacities and on the dates indicated:

<TABLE>
<CAPTION>

 SIGNATURE                                  TITLE                                        DATE
 ---------                                  -----                                        ----
<S>                                         <C>                                          <C>

 /s/ Michael G. Clark
 -------------------------------------
 Michael G. Clark                           President                                    November 19, 2007

 /s/ Paul H. Schubert
 -------------------------------------
 Paul H. Schubert                           Chief Financial Officer and Treasurer        November 19, 2007

 /s/Henry P. Becton, Jr.
 -------------------------------------
 Henry P. Becton, Jr.*                      Trustee                                      November 19, 2007

 /s/Dawn-Marie Driscoll
 -------------------------------------
 Dawn-Marie Driscoll*                       Chairperson and Trustee                      November 19, 2007

 /s/Keith R. Fox
 -------------------------------------
 Keith R. Fox*                              Trustee                                      November 19, 2007

 /s/Kenneth C. Froewiss
 -------------------------------------
 Kenneth C. Froewiss*                       Trustee                                      November 19, 2007

 /s/Martin J. Gruber
 -------------------------------------
 Martin J. Gruber*                          Trustee                                      November 19, 2007

 /s/Richard J. Herring
 -------------------------------------
 Richard J. Herring*                        Trustee                                      November 19, 2007

 /s/Graham E. Jones
 -------------------------------------
 Graham E. Jones*                           Trustee                                      November 19, 2007

 /s/Rebecca W. Rimel
 -------------------------------------
 Rebecca W. Rimel*                          Trustee                                      November 19, 2007

 /s/Philip Saunders, Jr.
 -------------------------------------
 Philip Saunders, Jr.*                      Trustee                                      November 19, 2007


<PAGE>
 SIGNATURE                                  TITLE                                        DATE
 ---------                                  -----                                        ----
 /s/William N. Searcy, Jr.
 -------------------------------------
 William N. Searcy, Jr.*                    Trustee                                      November 19, 2007

 /s/Jean Gleason Stromberg
 -------------------------------------
 Jean Gleason Stromberg*                    Trustee                                      November 19, 2007

 /s/Axel Schwarzer
 -------------------------------------
 Axel Schwarzer*                            Trustee                                      November 19, 2007

 /s/Carl W. Vogt
 -------------------------------------
 Carl W. Vogt*                              Trustee                                      November 19, 2007
</TABLE>


*By:     /s/ Caroline Pearson
----     --------------------
         Caroline Pearson**
         Assistant Secretary

**    Attorney-in-fact pursuant to the powers of attorney as contained in and
      incorporated by reference to Post Effective Amendment No. 93 to the
      Registration Statement, as filed on September 28, 2006.

<PAGE>


                                                               File No. 2-36238
                                                               File No. 811-2021



                       SECURITIES AND EXCHANGE COMMISSION

                             WASHINGTON, D.C. 20549





                                    EXHIBITS

                                       TO

                                    FORM N-1A



                         POST-EFFECTIVE AMENDMENT NO. 99

                            TO REGISTRATION STATEMENT

                                      UNDER

                           THE SECURITIES ACT OF 1933

                                       AND

                                AMENDMENT NO. 83

                            TO REGISTRATION STATEMENT

                                      UNDER

                       THE INVESTMENT COMPANY ACT OF 1940



                              DWS SECURITIES TRUST


                                       9
<PAGE>



                              DWS SECURITIES TRUST
                              --------------------

                                  EXHIBIT INDEX
                                  -------------

                                     (f)(1)
                                     (f)(2)








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