485BPOS

Filed electronically with the Securities and Exchange Commission on October 9, 2013

 File No. 002-36238

   File No. 811-02021

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D. C. 20549

FORM N-1A

REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933	| X |
Pre-Effective Amendment No.  ___	|__|
Post-Effective Amendment No. 128	| X |
and/or
REGISTRATION STATEMENT UNDER THE INVESTMENT COMPANY ACT OF 1940	| X |
Amendment No. 112
DWS Securities Trust (Exact Name of Registrant as Specified in Charter)
345 Park Avenue, New York, NY  10154 (Address of Principal Executive Offices)   (Zip Code)
Registrant’s Telephone Number, including Area Code:  (617) 295-1000
John Millette Vice President and Secretary One Beacon Street Boston, MA 02108 (Name and Address of Agent for Service)

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

/ X /	Immediately upon filing pursuant to paragraph (b)
/___/	On ______________ 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) 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

This filing relates solely to the following Fund, a series of the Registrant:

·   DWS RREEF Real Estate Securities Income Fund: Class A, Class C, Institutional Class and Class S

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 8th day of October 2013.

DWS SECURITIES TRUST

By:  /s/Robert Kendall

Robert Kendall*

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:

SIGNATURE	TITLE		DATE
/s/Robert Kendall
Robert Kendall*		President		October 8, 2013
/s/Paul H. Schubert
Paul H. Schubert		Chief Financial Officer and Treasurer		October 8, 2013
/s/John W. Ballantine
John W. Ballantine*		Trustee		October 8, 2013
/s/Henry P. Becton, Jr.
Henry P. Becton, Jr.*		Trustee		October 8, 2013
/s/Dawn-Marie Driscoll
Dawn-Marie Driscoll*		Trustee		October 8, 2013
/s/Keith R. Fox
Keith R. Fox*		Trustee		October 8, 2013
/s/Paul K. Freeman
Paul K. Freeman*		Trustee		October 8, 2013
/s/Kenneth C. Froewiss
Kenneth C. Froewiss*		Chairperson and Trustee		October 8, 2013
/s/Richard J. Herring
Richard J. Herring*		Trustee		October 8, 2013
/s/William McClayton
William McClayton*		Vice Chairperson and Trustee		October 8, 2013
/s/Rebecca W. Rimel
Rebecca W. Rimel*		Trustee		October 8, 2013
/s/William N. Searcy, Jr.
William N. Searcy, Jr.*		Trustee		October 8, 2013
/s/Jean Gleason Stromberg
Jean Gleason Stromberg*		Trustee		October 8, 2013
/s/Robert H. Wadsworth
Robert H. Wadsworth*		Trustee		October 8, 2013

*By:           

/s/Caroline Pearson

Caroline Pearson **

Chief Legal Officer

** Attorney-in-fact pursuant to the powers of attorney as filed herein; and that are incorporated herein by reference to Post-Effective Amendment No. 100 to the Registration Statement as filed on September 26, 2008.

Cash Account Trust

Cash Management Portfolio

Cash Reserve Fund, Inc.

DWS Equity 500 Index Portfolio

DWS Global High Income Fund, Inc.

DWS Global/International Fund, Inc.

DWS High Income Opportunities Fund, Inc.

DWS High Income Trust

DWS Income Trust

DWS Institutional Funds

DWS International Fund, Inc.

DWS Investment Trust

DWS Investments VIT Funds

DWS Market Trust

DWS Money Funds

DWS Money Market Trust

DWS Multi-Market Income Trust

DWS Municipal Income Trust

DWS Municipal Trust

DWS Portfolio Trust

DWS Securities Trust

DWS State Tax-Free Income Series

DWS Strategic Income Trust

DWS Strategic Municipal Income Trust

DWS Target Date Series

DWS Target Fund

DWS Tax Free Trust

DWS Value Series, Inc.

DWS Variable Series I

DWS Variable Series II

Investors Cash Trust

Tax-Exempt California Money Market Fund

(each a “Fund”)

Power of Attorney

KNOW ALL PERSONS BY THESE PRESENTS, that the following person, whose signature appears below, does hereby constitute and appoint Scott Hogan, John Millette and Caroline Pearson, and each of them, severally, with full powers of substitution, his true and lawful attorney and agent to execute in his name, place and stead (in such capacity) any and all amendments to enable the Fund to comply with the Securities Act of 1933, as amended (the “1933 Act”) and/or the Investment Company Act of 1940, as amended (the “1940 Act”), and any rules, regulations or requirements of the Securities and Exchange Commission in respect thereof, in connection with the Fund’s Registration Statement pursuant to the 1933 Act and/or the 1940 Act, together with any and all pre- and post-effective amendments thereto, including specifically, but without limiting the generality of the foregoing, the power and authority to sign in the name and on behalf of the undersigned as President of the Fund such Registration Statement and any and all such pre- and post-effective amendments filed with the Securities and Exchange Commission under the 1933 Act and/or the 1940 Act, and any other instruments or documents related thereto, and the undersigned does hereby ratify and confirm all that each said attorney-in-fact and agent, or may substitute or substitutes therefor, shall lawfully do or cause to be done by virtue hereof.

SIGNATURE	TITLE	DATE
/s/Robert Kendall Robert Kendall	President	October 3, 2013

DWS FUNDS BOARD

CERTIFICATE OF THE SECRETARY

I, John Millette, do hereby certify as follows:

1.   That I am the duly elected Secretary of the Funds listed on the attached Appendix A, (each a “Fund,” and each Fund’s underlying portfolios, if applicable, a “Series”);

2.   I further certify that the following is a complete and correct copy of resolutions adopted by all of the members of the Board of Directors/Trustees of the Funds by written consent effective October 3, 2013, and that such resolutions have not been amended and are in full force and effect:

WHEREAS, the President of the Fund, Robert Kendall, desires to execute a Power of Attorney and thereby delegate legal authority to the below-designated individuals to sign Registration Statements, including any amendments, on his behalf:

NOW THEREFORE BE IT:

RESOLVED, that the following individuals be, and they hereby are, and each of them hereby is, given a Power of Attorney in substantially the form presented to the Board, with such changes as the officers, with the advice of counsel, shall recommend, to sign the Fund’s Registration Statements, including any amendments:

Scott Hogan

John Millette

Caroline Pearson; and

FURTHER RESOLVED, that any Registration Statement signed pursuant to such Power of Attorney shall comply with Rule 483 (b) of the Securities Act of 1933 as amended, including, but not limited to the inclusion of: (1) a copy of the authorizing Power of Attorney; and (2) a certified copy of the resolutions of the Board authorizing such delegation as Exhibits thereto.

IN WITNESS WHEREOF, I hereunto set my hand this third day of October, 2013.

/s/John Millette

John Millette

Secretary

APPENDIX A

CASH ACCOUNT TRUST, and its series: Government & Agency Securities Portfolio Money Market Portfolio Tax-Exempt Portfolio   CASH MANAGEMENT PORTFOLIO   CASH RESERVE FUND, INC., and its series: Prime Series   DWS EQUITY 500 INDEX PORTFOLIO   DWS GLOBAL HIGH INCOME FUND, INC.   DWS GLOBAL/INTERNATIONAL FUND, INC., and its series: DWS Enhanced Emerging Markets Fixed Income Fund DWS Enhanced Global Bond Fund DWS Global Growth Fund DWS Global Small Cap Growth Fund DWS RREEF Global Infrastructure Fund   DWS HIGH INCOME OPPORTUNITIES FUND, INC.   DWS HIGH INCOME TRUST   DWS INCOME TRUST, and its series: DWS Core Fixed Income Fund DWS Global High Income Fund DWS Global Inflation Fund DWS GNMA Fund DWS High Income Fund DWS Short Duration Fund DWS Strategic Government Securities Fund DWS Ultra-Short Duration Fund DWS Unconstrained Income Fund   DWS INSTITUTIONAL FUNDS, and its series: DWS EAFE Equity Index Fund DWS Equity 500 Index Fund DWS S&P 500 Index Fund DWS U.S. Bond Index Fund   DWS PORTFOLIO TRUST, and its series: DWS Core Plus Income Fund DWS Floating Rate Fund           DWS INTERNATIONAL FUND, INC., and its series: DWS Emerging Markets Equity Fund DWS Global Equity Fund DWS International Fund DWS International Value Fund DWS Latin America Equity Fund DWS World Dividend Fund   DWS INVESTMENT TRUST, and its series: DWS Capital Growth Fund DWS Core Equity Fund DWS Large Cap Focus Growth Fund DWS Mid Cap Growth Fund DWS Small Cap Core Fund DWS Small Cap Growth Fund   DWS INVESTMENTS VIT FUNDS, and its series: DWS Equity 500 Index VIP DWS Small Cap Index VIP   DWS MARKET TRUST, and its series: DWS Alternative Asset Allocation Fund DWS Diversified Market Neutral Fund DWS Global Income Builder Fund DWS Select Alternative Allocation Fund   DWS MONEY FUNDS, and its series: DWS Money Market Prime Series   DWS MONEY MARKET TRUST, and its series Cash Management Fund Cash Reserve Fund Institutional Daily Assets Fund Institutional DWS Money Market Series NY Tax Free Money Fund Tax Free Money Fund Investment   DWS MULTI-MARKET INCOME TRUST   DWS MUNICIPAL INCOME TRUST   DWS MUNICIPAL TRUST, and its series: DWS Managed Municipal Bond Fund DWS Short-Term Municipal Bond Fund DWS Strategic High Yield Tax-Free Fund   DWS TAX FREE TRUST, and its series DWS Intermediate Tax/AMT Free Fund        

DWS SECURITIES TRUST, and its series: DWS Communications Fund DWS Enhanced Commodity Strategy Fund DWS Gold & Precious Metals Fund DWS Health Care Fund DWS RREEF Global Real Estate Securities Fund DWS RREEF Real Estate Securities Fund DWS RREEF Real Estate Securities Income Fund DWS Technology Fund DWS STATE TAX-FREE INCOME SERIES, and its series: DWS California Tax-Free Income Fund DWS Massachusetts Tax-Free Fund DWS New York Tax-Free Income Fund DWS STRATEGIC INCOME TRUST DWS STRATEGIC MUNICIPAL INCOME TRUST DWS TARGET DATE SERIES, and its series: DWS LifeCompass 2015 Fund DWS LifeCompass 2020 Fund DWS LifeCompass 2030 Fund DWS LifeCompass 2040 Fund DWS LifeCompass Retirement Fund DWS TARGET FUND, and its series: DWS Target 2014 Fund  DWS VALUE SERIES, INC. and its series: DWS Equity Dividend Fund DWS Large Cap Value Fund DWS Mid Cap Value Fund DWS Small Cap Value Fund DWS VARIABLE SERIES I, and its series DWS Bond VIP DWS Capital Growth VIP DWS Core Equity VIP DWS Global Small Cap Growth VIP DWS International VIP DWS VARIABLE SERIES II, and its series DWS Alternative Asset Allocation VIP DWS Global Equity VIP DWS Global Growth VIP DWS Global Income Builder VIP DWS Government & Agency Securities VIP DWS High Income VIP DWS Large Cap Value VIP DWS Money Market VIP DWS Small Mid Cap Growth VIP DWS Small Mid Cap Value VIP DWS Unconstrained Income VIP INVESTORS CASH TRUST, and its series: Central Cash Management Fund DWS Variable NAV Money Fund Treasury Portfolio TAX-EXEMPT CALIFORNIA MONEY MARKET FUND

EXHIBIT INDEX

Index No.	Description of Exhibit
EX-101.INS	XBRL Instance Document
EX-101.SCH	XBRL Taxonomy Extension Schema Document
EX-101.CAL	XBRL Taxonomy Extension Calculation Linkbase
EX-101.DEF	XBRL Taxonomy Extension Definition Linkbase
EX-101.LAB	XBRL Taxonomy Extension Labels Linkbase
EX-101.PRE	XBRL Taxonomy Extension Presentation Linkbase

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	DWS SECURITIES TRUST
Prospectus Date	rr_ProspectusDate	Sep. 23, 2013
Document Creation Date	dei_DocumentCreationDate	Sep. 04, 2013

XML

DWS RREEF Real Estate Securities Income Fund

DWS RREEF Real Estate Securities Income Fund

Investment Objective

The fund's investment objective is to seek current income with capital appreciation.

Fees and Expenses of the Fund

These are the fees and expenses you may pay when you buy and hold shares. You may qualify for sales charge discounts if you and your immediate family invest, or agree to invest in the future, at least $50,000 in DWS funds. More information about these and other discounts is available from your financial professional and in Choosing a Share Class (p. 12) and Purchase and Redemption of Shares in the fund's Statement of Additional Information (SAI) (p. II-15).

SHAREHOLDER FEES (paid directly from your investment)

Shareholder Fees DWS RREEF Real Estate Securities Income Fund (USD $)	Class A	Class C	INST Class	Class S
Maximum sales charge (load) imposed on purchases, as % of offering price	5.75%	none	none	none
Maximum deferred sales charge (load), as % of redemption proceeds	none	1.00%	none	none
Redemption/exchange fee on shares owned less than 15 days, as % of redemption proceeds	2.00%	2.00%	2.00%	2.00%
Account Maintenance Fee (annually, for fund balances below $10,000 and subject to certain exceptions)	20	20	none	20

ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a % of the value of your investment)

Annual Fund Operating Expenses DWS RREEF Real Estate Securities Income Fund		Class A	Class C	INST Class	Class S
Management fee		0.65%	0.65%	0.65%	0.65%
Distribution/service (12b-1) fees		0.25%	1.00%	none	none
Other expenses	[1]	1.49%	1.43%	1.34%	1.51%
Total annual fund operating expenses		2.39%	3.08%	1.99%	2.16%
Less expense waiver/reimbursement		0.99%	0.93%	0.84%	0.91%
Net annual fund operating expenses		1.40%	2.15%	1.15%	1.25%

The Advisor has contractually agreed through September 30, 2014 to waive and/or reimburse fund expenses to the extent necessary to maintain the fund's total annual operating expenses (excluding extraordinary expenses, taxes, brokerage and interest expense) at 1.40%, 2.15%, 1.15% and 1.25% for Class A, Class C, Institutional Class and Class S, respectively. The agreement may only be terminated with the consent of the fund's Board.

EXAMPLE

This Example is intended to help you compare the cost of investing in the fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the fund for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the fund's operating expenses (including one year of capped expenses in each period for each class) remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example DWS RREEF Real Estate Securities Income Fund (USD $)	Class A	Class C	INST Class	Class S
1 Year	709	318	117	127
3 Years	1,054	725	399	445

You would pay the following expenses if you did not redeem your shares:

Expense Example, No Redemption DWS RREEF Real Estate Securities Income Fund (USD $)	Class A	Class C	INST Class	Class S
1 Year	709	218	117	127
3 Years	1,054	725	399	445

PORTFOLIO TURNOVER

The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover may indicate higher transaction costs and may mean higher taxes if you are investing in a taxable account. These costs are not reflected in annual fund operating expenses or in the expense example, and can affect the fund's performance.

Since the fund has been operational for less than one year, portfolio turnover information is not available.

Principal Investment Strategy

Main investments. Under normal circumstances, the fund invests at least 80% of its net assets, plus the amount of any borrowing for investment purposes (calculated at the time of any investment), in securities of real estate investment trusts (REITs) and real estate companies. A company is considered to be a real estate company if, in the opinion of portfolio management, at least 50% of its revenues or 50% of the market value of its assets (in each case measured at the time of purchase) are attributed to the ownership, construction, management or sale of real estate or other activities primarily related to real estate. The fund will invest 25% or more of its total assets in securities of companies principally engaged in the real estate industry.

The fund typically invests in common and preferred stocks of REITs and real estate companies. The fund's REIT investments may include equity REITs, mortgage REITs and hybrid REITs. So-called equity REITs buy real estate and pay investors from the rents they receive and from any profits on the sale of their properties. So-called mortgage REITs lend money to real estate companies and pay investors from the interest they receive on those loans. So-called hybrid REITs engage in both owning real estate and making loans. While portfolio management expects that the fund's REIT investments will consist primarily of equity REITs, in changing market conditions, the fund may invest more significantly in other types of REITs.

The fund primarily invests in securities of US issuers, but may also invest in securities of Canadian issuers. The fund may invest to a lesser extent in non-US and non-Canadian issuers.

The fund may also invest a portion of its assets in other types of securities. These securities may include debt securities of REITs and real estate companies of any credit quality; securities of companies not principally engaged in the real estate industry, including companies principally engaged in infrastructure related activities; bonds, notes and short-term securities; and other similar securities. In addition, the fund may invest in commercial and other types of mortgage-backed securities and master limited partnerships (MLPs).

Derivatives. The fund may write (sell) covered call options on its portfolio securities with the goal of generating additional income from premiums received in connection with the options. Under specified circumstances, a call option gives the option buyer the right to buy, and obligates the option seller to sell, a security at an agreed-upon price (the strike price). Generally, a written call option is covered if the fund owns the security or instrument underlying the call option or has an absolute right to acquire that security or instrument without additional cash consideration. Portfolio management expects that the fund will typically write covered calls with respect to 20% to 50% of its assets. The fund is not subject to any limitations on its use of covered calls, however, and may use covered calls to a significantly greater or lesser extent, as determined by portfolio management.

When the fund sells a covered call option on a particular portfolio security, it may also buy a corresponding call option on the same security at a higher strike price. The purchased call option would typically expire in the same month as the original call option sold by the fund. By buying this second option, the fund preserves its ability to participate in any future appreciation of the underlying portfolio security above the second option's strike price. The premium the fund pays to purchase the second option would reduce, however, the premium income it receives when it sells the original covered call option.

Management process. Portfolio management looks for real estate securities it believes will provide superior returns over the long term, particularly companies portfolio management believes have the potential for stock price appreciation due to a relative mispricing between the private market value of the portfolio and the equity trading value and have a record of paying dividends.

To find these issuers, portfolio management tracks economic conditions and real estate market performance in major metropolitan areas and analyzes performance of various property types within those regions. For this analysis, portfolio management uses information from a nationwide network of real estate professionals to evaluate the holdings of real estate companies and REITs. Its analysis also considers the companies' management structures, financial structures and business strategies. Portfolio management also considers the effect of the real estate securities markets in general when making investment decisions. Lastly, portfolio management will look for securities portfolio management believes offer above-average yield opportunities.

Securities Lending. The fund may lend securities (up to one-third of total assets) to approved institutions.

Main Risks

There are several risk factors that could hurt the fund's performance, cause you to lose money or cause the fund's performance to trail that of other investments. The fund may not achieve its investment objective, and is not intended to be a complete investment program. An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency.

Stock market risk. When stock prices fall, you should expect the value of your investment to fall as well. Stock prices can be hurt by poor management on the part of the stock's issuer, shrinking product demand and other business risks. These factors may affect single companies as well as groups of companies. In addition, movements in financial markets may adversely affect a stock's price, regardless of how well the company performs.

Concentration risk. Any fund that concentrates in a particular segment of the market will generally be more volatile than a fund that invests more broadly. Any market price movements, regulatory or technological changes, or economic conditions affecting the particular segment of the market in which the fund concentrates may have a significant impact on the fund's performance.

In particular, real estate companies can be affected by the risks associated with direct ownership of real estate, such as general or local economic conditions, increases in property taxes and operating expenses, liability or losses owing to environmental problems, falling rents (whether owing to poor demand, increased competition, overbuilding, or limitations on rents), zoning changes, rising interest rates, and losses from casualty or condemnation. In addition, many real estate companies, including REITs, utilize leverage (and some may be highly leveraged), which increases investment risk. Further, REITs are dependent upon management skills and may not be diversified.

Dividend-paying stock risk. As a category, dividend-paying stocks may underperform non-dividend paying stocks (and the stock market as a whole) over any period of time. In addition, issuers of dividend-paying stocks may have discretion to defer or stop paying dividends for a stated period of time. If the dividend-paying stocks held by the fund reduce or stop paying dividends, the fund's ability to generate income may be adversely affected.

Preferred stocks, a type of dividend-paying stock, present certain additional risks. These risks include credit risk, interest rate risk, subordination to bonds and other debt securities in a company's capital structure, liquidity risk, and the risk of limited or no voting rights. Additionally, during periods of declining interest rates, there is a risk that an issuer may redeem its outstanding preferred stock. If this happens, the fund may be forced to reinvest in lower yielding securities. An issuer of preferred stock may have special redemption rights that, when exercised, may negatively impact the return of the preferred stock held by the fund.

Non-diversification risk. The fund is classified as non-diversified under the Investment Company Act of 1940, as amended. This means that the fund may invest in securities of relatively few issuers. Thus, the performance of one or a small number of portfolio holdings can affect overall performance.

Liquidity risk. In certain situations, it may be difficult or impossible to sell an investment in an orderly fashion at an acceptable price.

Security selection risk. The securities in the fund's portfolio may decline in value. Portfolio management could be wrong in its analysis of industries, companies, economic trends, the relative attractiveness of different securities or other matters.

Derivatives risk. Risks associated with derivatives include the risk that the derivative is not well correlated with the security, index or currency to which it relates; the risk that derivatives may result in losses or missed opportunities; the risk that the fund will be unable to sell the derivative because of an illiquid secondary market; the risk that a counterparty is unwilling or unable to meet its obligation; and the risk that the derivative transaction could expose the fund to the effects of leverage, which could increase the fund's exposure to the market and magnify potential losses.

Writing covered call options entails a number of risks. As a general matter, when the fund writes (sells) a covered call option, it agrees to deliver a security it already owns at a specified strike price on or before a predetermined date in the future in return for a premium. By writing a covered call option, the fund foregoes, during the option's life, the opportunity to benefit from an increase in the price of the underlying security above the option's strike price, but continues to bear the risk of a decline in the value of the underlying security. The price the fund realizes from the sale of the security upon exercise of the option could be substantially below its prevailing market price. Moreover, if a liquid market does not exist for a covered call option, the fund may be unable to close out the option transaction prior to its expiration date. Consequently, the fund may be unable to sell the underlying security until the option expires or is exercised. Lastly, by writing call options on its portfolio securities, the fund may be less likely to sell those securities to take advantage of new investment opportunities.

Foreign investment risk. The fund faces the risks inherent in foreign investing. Adverse political, economic or social developments could undermine the value of the fund's investments or prevent the fund from realizing the full value of its investments. Financial reporting standards for companies based in foreign markets differ from those in the US. Additionally, foreign securities markets generally are smaller and less liquid than US markets. To the extent that the fund invests in non-US dollar denominated foreign securities, changes in currency exchange rates may affect the US dollar value of foreign securities or the income or gain received on these securities.

Credit risk. The fund's performance could be hurt if an issuer of a debt security suffers an adverse change in financial condition that results in a payment default, security downgrade or inability to meet a financial obligation. Credit risk is greater for lower-rated securities.

Because the issuers of high-yield debt securities or junk bonds (debt securities rated below the fourth highest credit rating category) may be in uncertain financial health, the prices of their debt securities can be more vulnerable to bad economic news, or even the expectation of bad news, than investment-grade debt securities. High-yield debt securities are considered speculative, and credit risk for high-yield securities is greater than for higher-rated securities.

Interest rate risk. When interest rates rise, prices of debt securities generally decline. The longer the duration of the fund's debt securities, the more sensitive it will be to interest rate changes. (As a general rule, a 1% rise in interest rates means a 1% fall in value for every year of duration.)

Prepayment and extension risk. When interest rates fall, issuers of high interest debt obligations may pay off the debts earlier than expected (prepayment risk), and the fund may have to reinvest the proceeds at lower yields. When interest rates rise, issuers of lower interest debt obligations may pay off the debts later than expected (extension risk), thus keeping the fund's assets tied up in lower interest debt obligations. Ultimately, any unexpected behavior in interest rates could increase the volatility of the fund's share price and yield and could hurt fund performance. Prepayments could also create capital gains tax liability in some instances.

Securities lending risk. Any decline in the value of a portfolio security that occurs while the security is out on loan is borne by the fund and will adversely affect performance. Also, there may be delays in recovery of securities loaned or even a loss of rights in the collateral should the borrower of the securities fail financially while holding the security.

Counterparty risk. A financial institution or other counterparty with whom the fund does business, or that underwrites, distributes or guarantees any investments or contracts that the fund owns or is otherwise exposed to, may decline in financial health and become unable to honor its commitments. This could cause losses for the fund or could delay the return or delivery of collateral or other assets to the fund.

Past Performance

Since the fund is newly offered, performance information is not available.

[1] "Other Expenses" are based on estimated amounts for the current fiscal year.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	DWS SECURITIES TRUST
Prospectus Date	rr_ProspectusDate	Sep. 23, 2013
DWS RREEF Real Estate Securities Income Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	DWS RREEF Real Estate Securities Income Fund
Objective [Heading]	rr_ObjectiveHeading	Investment Objective
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The fund's investment objective is to seek current income with capital appreciation.
Expense [Heading]	rr_ExpenseHeading	Fees and Expenses of the Fund
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	These are the fees and expenses you may pay when you buy and hold shares. You may qualify for sales charge discounts if you and your immediate family invest, or agree to invest in the future, at least $50,000 in DWS funds. More information about these and other discounts is available from your financial professional and in Choosing a Share Class (p. 12) and Purchase and Redemption of Shares in the fund's Statement of Additional Information (SAI) (p. II-15).
Shareholder Fees Caption [Text]	rr_ShareholderFeesCaption	SHAREHOLDER FEES (paid directly from your investment)
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a % of the value of your investment)
Fee Waiver or Reimbursement over Assets, Date of Termination	rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination	September 30, 2014
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	PORTFOLIO TURNOVER
Portfolio Turnover [Text Block]	rr_PortfolioTurnoverTextBlock	The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover may indicate higher transaction costs and may mean higher taxes if you are investing in a taxable account. These costs are not reflected in annual fund operating expenses or in the expense example, and can affect the fund's performance. Since the fund has been operational for less than one year, portfolio turnover information is not available.
Expense Footnotes [Text Block]	rr_ExpenseFootnotesTextBlock	The Advisor has contractually agreed through September 30, 2014 to waive and/or reimburse fund expenses to the extent necessary to maintain the fund's total annual operating expenses (excluding extraordinary expenses, taxes, brokerage and interest expense) at 1.40%, 2.15%, 1.15% and 1.25% for Class A, Class C, Institutional Class and Class S, respectively. The agreement may only be terminated with the consent of the fund's Board.
Expense Breakpoint Discounts [Text]	rr_ExpenseBreakpointDiscounts	You may qualify for sales charge discounts if you and your immediate family invest, or agree to invest in the future, at least $50,000 in DWS funds.
Expense Breakpoint, Minimum Investment Required [Amount]	rr_ExpenseBreakpointMinimumInvestmentRequiredAmount	$ 50,000
Other Expenses, New Fund, Based on Estimates [Text]	rr_OtherExpensesNewFundBasedOnEstimates	"Other Expenses" are based on estimated amounts for the current fiscal year.
Expense Example [Heading]	rr_ExpenseExampleHeading	EXAMPLE
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	This Example is intended to help you compare the cost of investing in the fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the fund for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the fund's operating expenses (including one year of capped expenses in each period for each class) remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Expense Example, No Redemption Narrative [Text Block]	rr_ExpenseExampleNoRedemptionNarrativeTextBlock	You would pay the following expenses if you did not redeem your shares:
Strategy [Heading]	rr_StrategyHeading	Principal Investment Strategy
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	Main investments. Under normal circumstances, the fund invests at least 80% of its net assets, plus the amount of any borrowing for investment purposes (calculated at the time of any investment), in securities of real estate investment trusts (REITs) and real estate companies. A company is considered to be a real estate company if, in the opinion of portfolio management, at least 50% of its revenues or 50% of the market value of its assets (in each case measured at the time of purchase) are attributed to the ownership, construction, management or sale of real estate or other activities primarily related to real estate. The fund will invest 25% or more of its total assets in securities of companies principally engaged in the real estate industry. The fund typically invests in common and preferred stocks of REITs and real estate companies. The fund's REIT investments may include equity REITs, mortgage REITs and hybrid REITs. So-called equity REITs buy real estate and pay investors from the rents they receive and from any profits on the sale of their properties. So-called mortgage REITs lend money to real estate companies and pay investors from the interest they receive on those loans. So-called hybrid REITs engage in both owning real estate and making loans. While portfolio management expects that the fund's REIT investments will consist primarily of equity REITs, in changing market conditions, the fund may invest more significantly in other types of REITs. The fund primarily invests in securities of US issuers, but may also invest in securities of Canadian issuers. The fund may invest to a lesser extent in non-US and non-Canadian issuers. The fund may also invest a portion of its assets in other types of securities. These securities may include debt securities of REITs and real estate companies of any credit quality; securities of companies not principally engaged in the real estate industry, including companies principally engaged in infrastructure related activities; bonds, notes and short-term securities; and other similar securities. In addition, the fund may invest in commercial and other types of mortgage-backed securities and master limited partnerships (MLPs). Derivatives. The fund may write (sell) covered call options on its portfolio securities with the goal of generating additional income from premiums received in connection with the options. Under specified circumstances, a call option gives the option buyer the right to buy, and obligates the option seller to sell, a security at an agreed-upon price (the strike price). Generally, a written call option is covered if the fund owns the security or instrument underlying the call option or has an absolute right to acquire that security or instrument without additional cash consideration. Portfolio management expects that the fund will typically write covered calls with respect to 20% to 50% of its assets. The fund is not subject to any limitations on its use of covered calls, however, and may use covered calls to a significantly greater or lesser extent, as determined by portfolio management. When the fund sells a covered call option on a particular portfolio security, it may also buy a corresponding call option on the same security at a higher strike price. The purchased call option would typically expire in the same month as the original call option sold by the fund. By buying this second option, the fund preserves its ability to participate in any future appreciation of the underlying portfolio security above the second option's strike price. The premium the fund pays to purchase the second option would reduce, however, the premium income it receives when it sells the original covered call option. Management process. Portfolio management looks for real estate securities it believes will provide superior returns over the long term, particularly companies portfolio management believes have the potential for stock price appreciation due to a relative mispricing between the private market value of the portfolio and the equity trading value and have a record of paying dividends. To find these issuers, portfolio management tracks economic conditions and real estate market performance in major metropolitan areas and analyzes performance of various property types within those regions. For this analysis, portfolio management uses information from a nationwide network of real estate professionals to evaluate the holdings of real estate companies and REITs. Its analysis also considers the companies' management structures, financial structures and business strategies. Portfolio management also considers the effect of the real estate securities markets in general when making investment decisions. Lastly, portfolio management will look for securities portfolio management believes offer above-average yield opportunities. Securities Lending. The fund may lend securities (up to one-third of total assets) to approved institutions.
Strategy Portfolio Concentration [Text]	rr_StrategyPortfolioConcentration	The fund will invest 25% or more of its total assets in securities of companies principally engaged in the real estate industry.
Risk [Heading]	rr_RiskHeading	Main Risks
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	There are several risk factors that could hurt the fund's performance, cause you to lose money or cause the fund's performance to trail that of other investments. The fund may not achieve its investment objective, and is not intended to be a complete investment program. An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. Stock market risk. When stock prices fall, you should expect the value of your investment to fall as well. Stock prices can be hurt by poor management on the part of the stock's issuer, shrinking product demand and other business risks. These factors may affect single companies as well as groups of companies. In addition, movements in financial markets may adversely affect a stock's price, regardless of how well the company performs. Concentration risk. Any fund that concentrates in a particular segment of the market will generally be more volatile than a fund that invests more broadly. Any market price movements, regulatory or technological changes, or economic conditions affecting the particular segment of the market in which the fund concentrates may have a significant impact on the fund's performance. In particular, real estate companies can be affected by the risks associated with direct ownership of real estate, such as general or local economic conditions, increases in property taxes and operating expenses, liability or losses owing to environmental problems, falling rents (whether owing to poor demand, increased competition, overbuilding, or limitations on rents), zoning changes, rising interest rates, and losses from casualty or condemnation. In addition, many real estate companies, including REITs, utilize leverage (and some may be highly leveraged), which increases investment risk. Further, REITs are dependent upon management skills and may not be diversified. Dividend-paying stock risk. As a category, dividend-paying stocks may underperform non-dividend paying stocks (and the stock market as a whole) over any period of time. In addition, issuers of dividend-paying stocks may have discretion to defer or stop paying dividends for a stated period of time. If the dividend-paying stocks held by the fund reduce or stop paying dividends, the fund's ability to generate income may be adversely affected. Preferred stocks, a type of dividend-paying stock, present certain additional risks. These risks include credit risk, interest rate risk, subordination to bonds and other debt securities in a company's capital structure, liquidity risk, and the risk of limited or no voting rights. Additionally, during periods of declining interest rates, there is a risk that an issuer may redeem its outstanding preferred stock. If this happens, the fund may be forced to reinvest in lower yielding securities. An issuer of preferred stock may have special redemption rights that, when exercised, may negatively impact the return of the preferred stock held by the fund. Non-diversification risk. The fund is classified as non-diversified under the Investment Company Act of 1940, as amended. This means that the fund may invest in securities of relatively few issuers. Thus, the performance of one or a small number of portfolio holdings can affect overall performance. Liquidity risk. In certain situations, it may be difficult or impossible to sell an investment in an orderly fashion at an acceptable price. Security selection risk. The securities in the fund's portfolio may decline in value. Portfolio management could be wrong in its analysis of industries, companies, economic trends, the relative attractiveness of different securities or other matters. Derivatives risk. Risks associated with derivatives include the risk that the derivative is not well correlated with the security, index or currency to which it relates; the risk that derivatives may result in losses or missed opportunities; the risk that the fund will be unable to sell the derivative because of an illiquid secondary market; the risk that a counterparty is unwilling or unable to meet its obligation; and the risk that the derivative transaction could expose the fund to the effects of leverage, which could increase the fund's exposure to the market and magnify potential losses. Writing covered call options entails a number of risks. As a general matter, when the fund writes (sells) a covered call option, it agrees to deliver a security it already owns at a specified strike price on or before a predetermined date in the future in return for a premium. By writing a covered call option, the fund foregoes, during the option's life, the opportunity to benefit from an increase in the price of the underlying security above the option's strike price, but continues to bear the risk of a decline in the value of the underlying security. The price the fund realizes from the sale of the security upon exercise of the option could be substantially below its prevailing market price. Moreover, if a liquid market does not exist for a covered call option, the fund may be unable to close out the option transaction prior to its expiration date. Consequently, the fund may be unable to sell the underlying security until the option expires or is exercised. Lastly, by writing call options on its portfolio securities, the fund may be less likely to sell those securities to take advantage of new investment opportunities. Foreign investment risk. The fund faces the risks inherent in foreign investing. Adverse political, economic or social developments could undermine the value of the fund's investments or prevent the fund from realizing the full value of its investments. Financial reporting standards for companies based in foreign markets differ from those in the US. Additionally, foreign securities markets generally are smaller and less liquid than US markets. To the extent that the fund invests in non-US dollar denominated foreign securities, changes in currency exchange rates may affect the US dollar value of foreign securities or the income or gain received on these securities. Credit risk. The fund's performance could be hurt if an issuer of a debt security suffers an adverse change in financial condition that results in a payment default, security downgrade or inability to meet a financial obligation. Credit risk is greater for lower-rated securities. Because the issuers of high-yield debt securities or junk bonds (debt securities rated below the fourth highest credit rating category) may be in uncertain financial health, the prices of their debt securities can be more vulnerable to bad economic news, or even the expectation of bad news, than investment-grade debt securities. High-yield debt securities are considered speculative, and credit risk for high-yield securities is greater than for higher-rated securities. Interest rate risk. When interest rates rise, prices of debt securities generally decline. The longer the duration of the fund's debt securities, the more sensitive it will be to interest rate changes. (As a general rule, a 1% rise in interest rates means a 1% fall in value for every year of duration.) Prepayment and extension risk. When interest rates fall, issuers of high interest debt obligations may pay off the debts earlier than expected (prepayment risk), and the fund may have to reinvest the proceeds at lower yields. When interest rates rise, issuers of lower interest debt obligations may pay off the debts later than expected (extension risk), thus keeping the fund's assets tied up in lower interest debt obligations. Ultimately, any unexpected behavior in interest rates could increase the volatility of the fund's share price and yield and could hurt fund performance. Prepayments could also create capital gains tax liability in some instances. Securities lending risk. Any decline in the value of a portfolio security that occurs while the security is out on loan is borne by the fund and will adversely affect performance. Also, there may be delays in recovery of securities loaned or even a loss of rights in the collateral should the borrower of the securities fail financially while holding the security. Counterparty risk. A financial institution or other counterparty with whom the fund does business, or that underwrites, distributes or guarantees any investments or contracts that the fund owns or is otherwise exposed to, may decline in financial health and become unable to honor its commitments. This could cause losses for the fund or could delay the return or delivery of collateral or other assets to the fund.
Risk Lose Money [Text]	rr_RiskLoseMoney	There are several risk factors that could hurt the fund's performance, cause you to lose money or cause the fund's performance to trail that of other investments.
Risk Nondiversified Status [Text]	rr_RiskNondiversifiedStatus	Non-diversification risk. The fund is classified as non-diversified under the Investment Company Act of 1940, as amended. This means that the fund may invest in securities of relatively few issuers. Thus, the performance of one or a small number of portfolio holdings can affect overall performance.
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	Past Performance
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	Since the fund is newly offered, performance information is not available.
Performance One Year or Less [Text]	rr_PerformanceOneYearOrLess	Since the fund is newly offered, performance information is not available.
DWS RREEF Real Estate Securities Income Fund | Class A
Risk/Return:	rr_RiskReturnAbstract
Maximum sales charge (load) imposed on purchases, as % of offering price	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	5.75%
Maximum deferred sales charge (load), as % of redemption proceeds	rr_MaximumDeferredSalesChargeOverOther	none
Redemption/exchange fee on shares owned less than 15 days, as % of redemption proceeds	rr_RedemptionFeeOverRedemption	2.00%
Account Maintenance Fee (annually, for fund balances below $10,000 and subject to certain exceptions)	rr_MaximumAccountFee	20
Management fee	rr_ManagementFeesOverAssets	0.65%
Distribution/service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other expenses	rr_OtherExpensesOverAssets	1.49%	[1]
Total annual fund operating expenses	rr_ExpensesOverAssets	2.39%
Less expense waiver/reimbursement	rr_FeeWaiverOrReimbursementOverAssets	0.99%
Net annual fund operating expenses	rr_NetExpensesOverAssets	1.40%
1 Year	rr_ExpenseExampleYear01	709
3 Years	rr_ExpenseExampleYear03	1,054
1 Year	rr_ExpenseExampleNoRedemptionYear01	709
3 Years	rr_ExpenseExampleNoRedemptionYear03	1,054
DWS RREEF Real Estate Securities Income Fund | Class C
Risk/Return:	rr_RiskReturnAbstract
Maximum sales charge (load) imposed on purchases, as % of offering price	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Maximum deferred sales charge (load), as % of redemption proceeds	rr_MaximumDeferredSalesChargeOverOther	1.00%
Redemption/exchange fee on shares owned less than 15 days, as % of redemption proceeds	rr_RedemptionFeeOverRedemption	2.00%
Account Maintenance Fee (annually, for fund balances below $10,000 and subject to certain exceptions)	rr_MaximumAccountFee	20
Management fee	rr_ManagementFeesOverAssets	0.65%
Distribution/service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	1.00%
Other expenses	rr_OtherExpensesOverAssets	1.43%	[1]
Total annual fund operating expenses	rr_ExpensesOverAssets	3.08%
Less expense waiver/reimbursement	rr_FeeWaiverOrReimbursementOverAssets	0.93%
Net annual fund operating expenses	rr_NetExpensesOverAssets	2.15%
1 Year	rr_ExpenseExampleYear01	318
3 Years	rr_ExpenseExampleYear03	725
1 Year	rr_ExpenseExampleNoRedemptionYear01	218
3 Years	rr_ExpenseExampleNoRedemptionYear03	725
DWS RREEF Real Estate Securities Income Fund | INST Class
Risk/Return:	rr_RiskReturnAbstract
Maximum sales charge (load) imposed on purchases, as % of offering price	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Maximum deferred sales charge (load), as % of redemption proceeds	rr_MaximumDeferredSalesChargeOverOther	none
Redemption/exchange fee on shares owned less than 15 days, as % of redemption proceeds	rr_RedemptionFeeOverRedemption	2.00%
Account Maintenance Fee (annually, for fund balances below $10,000 and subject to certain exceptions)	rr_MaximumAccountFee	none
Management fee	rr_ManagementFeesOverAssets	0.65%
Distribution/service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	none
Other expenses	rr_OtherExpensesOverAssets	1.34%	[1]
Total annual fund operating expenses	rr_ExpensesOverAssets	1.99%
Less expense waiver/reimbursement	rr_FeeWaiverOrReimbursementOverAssets	0.84%
Net annual fund operating expenses	rr_NetExpensesOverAssets	1.15%
1 Year	rr_ExpenseExampleYear01	117
3 Years	rr_ExpenseExampleYear03	399
1 Year	rr_ExpenseExampleNoRedemptionYear01	117
3 Years	rr_ExpenseExampleNoRedemptionYear03	399
DWS RREEF Real Estate Securities Income Fund | Class S
Risk/Return:	rr_RiskReturnAbstract
Maximum sales charge (load) imposed on purchases, as % of offering price	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Maximum deferred sales charge (load), as % of redemption proceeds	rr_MaximumDeferredSalesChargeOverOther	none
Redemption/exchange fee on shares owned less than 15 days, as % of redemption proceeds	rr_RedemptionFeeOverRedemption	2.00%
Account Maintenance Fee (annually, for fund balances below $10,000 and subject to certain exceptions)	rr_MaximumAccountFee	20
Management fee	rr_ManagementFeesOverAssets	0.65%
Distribution/service (12b-1) fees	rr_DistributionAndService12b1FeesOverAssets	none
Other expenses	rr_OtherExpensesOverAssets	1.51%	[1]
Total annual fund operating expenses	rr_ExpensesOverAssets	2.16%
Less expense waiver/reimbursement	rr_FeeWaiverOrReimbursementOverAssets	0.91%
Net annual fund operating expenses	rr_NetExpensesOverAssets	1.25%
1 Year	rr_ExpenseExampleYear01	127
3 Years	rr_ExpenseExampleYear03	445
1 Year	rr_ExpenseExampleNoRedemptionYear01	127
3 Years	rr_ExpenseExampleNoRedemptionYear03	$ 445

[1] "Other Expenses" are based on estimated amounts for the current fiscal year.

XML

Document and Entity Information	12 Months Ended
	Sep. 23, 2013
Risk/Return:
Document Type	485BPOS
Document Period End Date	Sep. 04, 2013
Registrant Name	DWS SECURITIES TRUST
Central Index Key	0000088048
Amendment Flag	false
Document Creation Date	Sep. 04, 2013
Document Effective Date	Sep. 19, 2013
Prospectus Date	Sep. 23, 2013