UNITED STATES
	SECURITIES AND EXCHANGE COMMISSION
	Washington, D.C. 20549

	FORM 10-Q


[X]	Quarterly report pursuant to Section 13 or 15(d) of the Securities Exchange
Act of 1934
For the quarterly period ended March 31, 2006 or

[ ]	Transition report pursuant to Section 13 or 15(d) of the Securities
Exchange Act of 1934
For the transition period from                to

Commission File Number 0-18314

	DEAN WITTER PRINCIPAL PLUS FUND L.P.

	(Exact name of registrant as specified in its charter)

		Delaware						     13-3541588
(State or other jurisdiction of		   		  (I.R.S. Employer
incorporation or organization)			       Identification No.)


Demeter Management Corporation
330 Madison Avenue, 8th Floor
New York, NY							      	10017
(Address of principal executive offices)	  	         (Zip Code)

Registrant?s telephone number, including area code       (212) 905-2700



(Former name, former address, and former fiscal year, if changed since last
report)

Indicate by check-mark whether the
registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the
 Securities Exchange Act of 1934 during
the preceding 12 months (or for such shorter period that the registrant was
required to file such reports), and (2) has been subject to such filing
requirements for the past 90 days.

Yes    X       	No__________

Indicate by check-mark whether the registrant is a large accelerated filer, an
accelerated filer, or a non-accelerated filer.  See definition of ?accelerated
filer and large accelerated filer? in Rule 12b-2 of the Exchange Act.  (Check
one):

Large accelerated filer___Accelerated filer____Non-accelerated filer X

Indicate by check-mark whether the registrant is a shell company (as defined
in Rule 12b-2 of the Exchange Act).  Yes___  No X


<page> <table> 	DEAN WITTER PRINCIPAL PLUS FUND L.P.

	INDEX TO QUARTERLY REPORT ON FORM 10-Q

	March 31, 2006

<caption>


PART I. FINANCIAL INFORMATION

Item 1. Financial Statements

				<c>
	Consolidated Statements of Financial Condition as of
	March 31, 2006 (Unaudited) and December 31, 2005..............2

	Consolidated Statements of Operations for the Quarters
	Ended March 31, 2006 and 2005 (Unaudited).....................3

	Consolidated Statements of Changes in Partners? Capital for
the Quarters Ended March 31, 2006 and 2005 (Unaudited)........4

	Consolidated Statements of Cash Flows for the Quarters
	Ended March 31, 2006 and 2005 (Unaudited)................... .5

	Notes to Consolidated Financial Statements (Unaudited).....6-11

Item 2.	Management?s Discussion and Analysis of
			Financial Condition and Results of Operations........12-21

Item 3.	Quantitative and Qualitative Disclosures about
			Market Risk..........................................22-35

Item 4.	Controls and Procedures.................................35


PART II. OTHER INFORMATION

Item 1A.Risk Factors............................................36

Item 5.	Other Information.......................................36

Item 6.	Exhibits.............................................36-37


</table>


<page> <table> PART I.  FINANCIAL INFORMATION

Item 1.  Financial Statements

	DEAN WITTER PRINCIPAL PLUS FUND L.P.
	CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION
<caption>
	                       March 31,	     December 31,
                                                2006      	    2005
	                      $	    $
	                        (Unaudited)
ASSETS

	<c>	<c>
Equity in futures interests trading accounts:
	Unrestricted cash	15,335,596	16,730,219
    Restricted cash						               960,400	       720,459

	     Total cash	  16,295,996	   17,450,678

	Net unrealized gain (loss) on open contracts (MS&Co.)	245,306	     (122,269)
	Net unrealized gain on open contracts (MSIL)	          5,614   	         11,578

	     Total net unrealized gain (loss) on open contracts	       250,920	      (110,691)

	     Total Trading Equity	16,546,916	  17,339,987

Interest receivable (Morgan Stanley DW)	        57,728	        53,551

	     Total Assets	  16,604,644	 17,393,538

LIABILITIES AND PARTNERS? CAPITAL

Liabilities

Redemptions payable	223,933	277,078
Accrued administrative expenses	123,949	120,879
Accrued brokerage fees (Morgan Stanley DW)	54,936	57,576
Accrued management fees  	       13,734	       14,393

	     Total Liabilities                        416,552	      469,926

Minority Interest	         3,056	          2,754

Partners? Capital
Limited Partners (8,400.749 and
   8,819.337 Units, respectively)	15,979,546	16,716,099
General Partner (108.030 Units)	      205,490	       204,759

	     Total Partners? Capital	   16,185,036  	   16,920,858

	     Total Liabilities and Partners? Capital	   16,604,644	   17,393,538


NET ASSET VALUE PER UNIT 	       1,902.16	       1,895.39

<fn>
	The accompanying notes are an integral part
	of these consolidated financial statements.
</table>


	<page. <table> DEAN WITTER PRINCIPAL PLUS FUND L.P.
	CONSOLIDATED STATEMENTS OF OPERATIONS
(Unaudited)

	<caption>

  	   	    For the Quarters Ended March 31,


                                                                         		          2006    	      2005
                                                                               	                      $		          $

		<c>		<c>
INVESTMENT INCOME
	Interest income (Morgan Stanley DW)		      159,682			   110,293

EXPENSES
	Brokerage fees (Morgan Stanley DW)		167,208	210,468
	Management fees	     	 41,802	   52,617
	Administrative expenses		25,000	28,000
	Transaction fees and costs		        12,516	     10,544

		   Total Expenses		      246,526	   301,629

NET INVESTMENT LOSS	      (86,844)	   (191,336)

TRADING RESULTS
Trading profit (loss):
	Realized			(217,664)	(310,845)
	Net change in unrealized		     361,611	   (260,881)

    Total Trading Results		     143,947	   (571,726)

NET INCOME (LOSS) BEFORE MINORITY INTEREST            57,103	               (763,062)

Less:  Minority Interest		            301	        (8,448)

NET INCOME (LOSS)		       56,802	   (754,614)

NET INCOME (LOSS) ALLOCATION

	Limited Partners                                                  		56,071 	     (744,063)
     	     General Partner       	                                            	731	       (10,551)

NET INCOME (LOSS) PER UNIT

	Limited  Partners                                                 		                    6.77	  (68.50)
	General Partner                                                  		                6.77  	  (68.50)
<fn>




The accompanying notes are an integral part
of these consolidated financial statements.

</table>


<page> <table> DEAN WITTER PRINCIPAL PLUS FUND L.P.
	CONSOLIDATED STATEMENTS OF CHANGES IN PARTNERS? CAPITAL
	For the Quarters Ended March 31, 2006 and 2005
	(Unaudited)

<caption>



	  Units of
	   Partnership	Limited	General
	   Interest   	Partners	Partner	   Total
		$	$	   $


	<c>	<c>	<c>	<c>
Partners? Capital,
	December 31, 2004	   11,303.801	21,965,072	          303,439
22,268,511

Net Loss                   	?		(744,063)	(10,551)	(754,614)

Redemptions	      (794.953)	 (1,531,299)                 ?      	  (1,531,299)

Partners? Capital,
	March 31, 2005  	          10,508.848	  19,689,710	  292,888	 19,982,598



Partners? Capital,
	December 31, 2005	   8,927.367	16,716,099	          204,759
16,920,858

Net Income                   	?		56,071	731	56,802

Redemptions	      (418.588)	 (792,624)                 ?      	  (792,624)

Partners? Capital,
	March 31, 2006  	          8,508.779	  15,979,546	  205,490	 16,185,036






<fn>








The accompanying notes are an integral part
	of these consolidated financial statements.
</table>


<page> <table> 	DEAN WITTER PRINCIPAL PLUS FUND L.P.
	CONSOLIDATED STATEMENTS OF CASH FLOWS
(Unaudited)



<caption>

	          For the Quarters Ended March 31,

	      2006     	      2005
	      $	      $


CASH FLOWS FROM OPERATING ACTIVITIES

			<c>	<c>
Net income (loss)	56,802	(754,614)
Noncash item included in net income (loss):
	Net change in unrealized	(361,611)	260,881

(Increase) decrease in operating assets:
	Restricted cash	(239,941)	392,883
	Interest receivable (Morgan Stanley DW)	(4,177)	(4,911)

Increase (decrease) in operating liabilities:
	Accrued administrative expenses	3,070	12,940
	Accrued brokerage fees (Morgan Stanley DW)	(2,640)	(8,884)
	Accrued management fees	          (659)	      (2,220)

Net cash used for operating activities	   (549,156)	   (103,925)


CASH FLOWS FROM FINANCING ACTIVITIES

Cash paid for redemptions of Units	(845,769)  	 (1,890,942)
Increase (decrease) in minority interest	          302	          (8,448)

Net cash used for financing activities	   (845,467)	  (1,899,390)

Net decrease in unrestricted cash	(1,394,623)	(2,003,315)

Unrestricted cash at beginning of period	   16,730,219	   21,677,025

Unrestricted cash at end of period	  15,335,596	  19,673,710




<fn>



	The accompanying notes are an integral part
	of these consolidated financial statements.

</table>


<page> DEAN WITTER PRINCIPAL PLUS FUND L.P.
NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

March 31, 2006

(Unaudited)

The unaudited consolidated financial statements contained herein
include, in the opinion of management, all adjustments necessary
for a fair presentation of the results of operations and financial
condition of Dean Witter Principal Plus Fund L.P. (the
?Partnership?).  The consolidated financial statements and
condensed notes herein should be read in conjunction with the
Partnership?s December 31, 2005 Annual Report on Form 10-K.
Certain prior year amounts relating to cash balances were
reclassified on the Consolidated Statements of Financial Condition
and the related Consolidated Statements of Cash Flows to conform to
2006 presentation. Such reclassifications have no impact on the
Partnership?s reported net income (loss).

1.  Organization
Dean Witter Principal Plus Fund L.P. is a Delaware limited
partnership organized in 1989 to engage primarily in the
speculative trading of futures contracts, options on futures
contracts, and forward contracts on physical commodities and other
commodity interests (collectively, ?Futures Interests?).



<page> DEAN WITTER PRINCIPAL PLUS FUND L.P.
NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)

The Partnership?s general partner is Demeter Management Corporation
(?Demeter?). The non-clearing commodity broker is Morgan Stanley
DW Inc. (?Morgan Stanley DW?).  The clearing commodity brokers
are Morgan Stanley & Co. Incorporated (?MS & Co.?) and Morgan
Stanley & Co. International Limited (?MSIL?).  Demeter, Morgan
Stanley DW, MS & Co., and MSIL are wholly-owned subsidiaries of
Morgan Stanley.  The trading advisor to the Partnership is SSARIS
Advisors, LLC (the ?Trading Advisor?).  Dean Witter Principal
Plus Fund Management L.P. (the ?Trading Company?), was
established solely to trade in Futures Interests on behalf of the
Partnership.

2.  Related Party Transactions
The Partnership?s and Trading Company?s cash is on deposit with
Morgan Stanley DW, MS & Co., and MSIL in futures, forwards, and
options trading accounts to meet margin requirements as needed.
Monthly, Morgan Stanley DW pays interest income on 100% and 90% of
the Partnership?s and the Trading Company?s, respectively, average
daily Net Assets as defined in the Limited Partnership Agreement
for the month at a prevailing rate on U.S. Treasury bills.  The
Trading Company pays brokerage fees to Morgan Stanley DW.



<page> DEAN WITTER PRINCIPAL PLUS FUND L.P.
NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)

3.  Financial Instruments
The Partnership trades Futures Interests.  Futures and forwards
represent contracts for delayed delivery of an instrument at a
specified date and price.  Risk arises from changes in the value of
these contracts and the potential inability of counterparties to
perform under the terms of the contracts.  There are numerous
factors which may significantly influence the market value of these
contracts, including interest rate volatility.



The market value of exchange-traded contracts is based on the
settlement price quoted by the exchange on the day with respect to
which market value is being determined.  If an exchange-traded
contract could not have been liquidated on such day due to the
operation of daily limits or other rules of the exchange, the
settlement price shall be the settlement price on the first
subsequent day on which the contract could be liquidated.  The
market value of off-exchange-traded contracts is based on the fair
market value quoted by the counterparty.


The Partnership?s contracts are accounted for on a trade-date
basis and marked to market on a daily basis.  The Partnership
accounts for its derivative investments in accordance with the

<page> DEAN WITTER PRINCIPAL PLUS FUND L.P.
NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)

provisions of Statement of Financial Accounting Standards No.
133, ?Accounting for Derivative Instruments and Hedging
Activities? (?SFAS No. 133?).  SFAS No. 133 defines a
derivative as a financial instrument or other contract that has
all three of the following characteristics:

1)	One or more underlying notional amounts or payment
provisions;
2)	Requires no initial net investment or a smaller initial net
investment than would be required relative to changes in
market factors;
3)	Terms require or permit net settlement.

Generally, derivatives include futures, forward, swaps or options
contracts, and other financial instruments with similar
characteristics such as caps, floors, and collars.

The net unrealized gains (losses) on open contracts, reported as a
component of ?Equity in futures interests trading accounts? on
the Consolidated Statements of Financial Condition, and their
longest contract maturities were as follows:






<page> DEAN WITTER PRINCIPAL PLUS FUND L.P.
NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)


	Net Unrealized Gains/(Losses)
	on Open Contracts	Longest Maturities
		Off-			Off-
	Exchange-	Exchange-		Exchange-	Exchange-
Date	 Traded 	 Traded 	Total	 Traded 	 Traded
	  $	   $	  $
Mar. 31, 2006	254,446	(3,526)	250,920	 Jun. 2006	Jun. 2006
Dec. 31, 2005	(114,913)        4,222		(110,691)  	Mar. 2006   Mar. 2006

The Partnership has credit risk associated with counterparty non-
performance.  As of the date of the financial statements, the
credit risk associated with the instruments in which the
Partnership trades is limited to the amounts reflected
in the Partnership?s Consolidated Statements of Financial
Condition.

The Partnership also has credit risk because Morgan Stanley DW, MS
& Co., and MSIL act as the futures commission merchants or the
counterparties, with respect to most of the Partnership?s assets.
Exchange-traded futures, forward, and futures-styled options
contracts are marked to market on a daily basis, with variations in
value settled on a daily basis.  Morgan Stanley DW, MS & Co., and
MSIL, each as a futures commission merchant for the Partnership?s
exchange-traded futures, forward, and futures-styled options
contracts, are required, pursuant to regulations of the Commodity
Futures Trading Commission (?CFTC?), to segregate from

<page> DEAN WITTER PRINCIPAL PLUS FUND L.P.
NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONCLUDED)

their own assets, and for the sole benefit of their commodity
customers, all funds held by them with respect to exchange-traded
futures, forward, and futures-styled options contracts, including
an amount equal to the net unrealized gains (losses) on all open
futures, forward, and futures-styled options contracts, which
funds, in the aggregate, totaled $16,550,442 and $17,335,765
at March 31, 2006 and December 31, 2005, respectively.  With
respect to the Partnership?s off-exchange-traded forward currency
contracts, there are no daily exchange-required settlements of
variation in value, nor is there any requirement that an amount
equal to the net unrealized gains (losses) on open forward
contracts be segregated.  However, the Partnership is required to
meet margin requirements equal to the net unrealized loss on open
contracts in the Partnership accounts with the counterparty, which
is accomplished by daily maintenance of the cash balance in a
custody account held at Morgan Stanley DW for the benefit of MS &
Co.  With respect to those off-exchange-traded forward currency
contracts, the Partnership is at risk to the ability of MS & Co.,
the sole counterparty on all such contracts, to perform. The
Partnership has a netting agreement with MS & Co. This agreement,
which seeks to reduce both the Partnership?s and MS & Co.?s
exposure to off-exchange-traded forward currency contracts, should
materially decrease the Partnership?s credit risk in the event of
MS & Co.?s bankruptcy or insolvency.


<page> Item 2.	MANAGEMENT?S DISCUSSION AND ANALYSIS OF FINANCIAL
	CONDITION AND RESULTS OF OPERATIONS


Liquidity.  The Partnership deposits its assets with Morgan Stanley
DW as non-clearing broker, and MS & Co. and MSIL as clearing
brokers in separate futures, forwards, and options trading accounts
established for the Trading Advisor.  Such assets are used as
margin to engage in trading and may be used as margin solely for
the Partnership?s trading. The assets are held in either non-
interest bearing bank accounts or in securities and instruments
permitted by the CFTC for investment of customer segregated or
secured funds.  Since the Partnership?s sole purpose is to trade in
futures, forwards, and options, it is expected that the Partnership
will continue to own such liquid assets for margin purposes.

The Partnership?s investment in futures, forwards, and options may,
from time to time, be illiquid.  Most U.S. futures exchanges limit
fluctuations in prices during a single day by regulations referred
to as ?daily price fluctuations limits? or ?daily limits?.
Trades may not be executed at prices beyond the daily limit.  If
the price for a particular futures or options contract has
increased or decreased by an amount equal to the daily limit,
positions in that futures or options contract can neither be taken
nor liquidated unless traders are willing to effect trades at or
within the limit.  Futures prices have occasionally moved the daily
limit for several consecutive days with little or no   <page>
trading. These market conditions could prevent the Partnership from
promptly liquidating its futures or options contracts and result in
restrictions on redemptions.

There is no limitation on daily price moves in trading forward
contracts on foreign currencies.  The markets for some world
currencies have low trading volume and are illiquid, which may
prevent the Partnership from trading in potentially profitable
markets or prevent the Partnership from promptly liquidating
unfavorable positions in such markets, subjecting it to substantial
losses.  Either of these market conditions could result in
restrictions on redemptions. For the periods covered by this
report, illiquidity has not materially affected the Partnership?s
assets.

There are no known material trends, demands, commitments, events,
or uncertainties at the present time that are reasonably likely to
result in the Partnership?s liquidity increasing or decreasing in
any material way.

Capital Resources.  The Partnership does not have, nor expects to
have, any capital assets.  Redemptions of units of limited
partnership interest (?Unit(s)?) in the future will affect the
amount of funds available for investments in futures, forwards, and
options in subsequent periods.  It is not possible to estimate
<page> the amount, and therefore the impact, of future  outflows of
Units.

There are no known material trends, favorable or unfavorable, that
would affect, nor any expected material changes to, the
Partnership?s capital resource arrangements at the present time.

Off-Balance Sheet Arrangements and Contractual Obligations.  The
Partnership does not have any off-balance sheet arrangements, nor
does it have contractual obligations or commercial commitments to
make future payments that would affect its liquidity or capital
resources.

Results of Operations
General.  The Partnership?s results depend on the Trading Advisor
and the ability of the Trading Advisor?s trading program to take
advantage of price movements in the futures, forwards, and options
markets.  The following presents a summary of the Partnership?s
operations for the three month periods ended March 31, 2006 and
2005, and a general discussion of its trading activities during
each period.  It is important to note, however, that the Trading
Advisor trades in various markets at different times and that prior
activity in a particular market does not mean that such market will
be actively traded by the Trading Advisor or will be profitable in
the future. Consequently, the results of operations of the
Partnership are difficult to discuss other than in the <page>
context of the Trading Advisor?s trading activities on behalf of
the Partnership during the period in question. Past performance is
no guarantee of future results.

The Partnership?s results of operations set forth in the
financial statements on pages 2 through 11 of this report are
prepared in accordance with accounting principles generally
accepted in the United States of America, which require the use
of certain accounting policies that affect the amounts reported
in these financial statements, including the following:  The
contracts the Partnership trades are accounted for on a trade-
date basis and marked to market on a daily basis. The difference
between their cost and market value is recorded on the
Consolidated Statements of Operations as ?Net change in
unrealized trading profit (loss)? for open (unrealized)
contracts, and recorded as ?Realized trading profit (loss)?
when open positions are closed out.  The sum of these amounts
constitutes the Partnership?s trading results.  The market value
of a futures contract is the settlement price on the exchange on
which that futures contract is traded on a particular day.  The
value of foreign currency forward contracts is based on the spot
rate as of the close of business.  Interest income, as well as
management fees, incentive fees, brokerage fees, and transaction
fees and costs of the Partnership are recorded on an accrual
basis.

<page> Demeter believes that, based on the nature of the operations
of the Partnership, no assumptions relating to the application of
critical accounting policies other than those presently used could
reasonably affect reported amounts.

For the Quarter Ended March 31, 2006
The Partnership recorded total trading results including interest
income totaling $303,629, expenses totaling $246,526, and
minority interest of $301, resulting in net income of $56,802
for the quarter ended March 31, 2006.  The Partnership?s net
asset value per Unit increased from $1,895.39 at December 31,
2005 to $1,902.16 at March 31, 2006.

The most significant trading gains of approximately 1.5% were
recorded in the global stock index futures markets from long
positions in S&P 500 Index futures as prices moved higher after a
weaker-than-expected December U.S. jobs report raised hopes the
U.S. Federal Reserve might end its cycle of interest rate hikes
sooner rather than later.  Prices were also pressured higher on
strong earnings announcements from several U.S. bell weather
companies.  Additional gains of approximately 0.3% were
experienced in the metals markets, during January and March, from
long futures positions in copper and zinc as prices strengthened
amid weak supplies, forecasts for continued buying by China, and
acceleration in demand from Japan, Europe, and the U.S.
Elsewhere in the metals markets, gains were recorded from long
<page> futures positions in silver and gold as precious metals
prices moved higher on persistent demand from foreign central
banks.  Silver prices were also pressured higher after news that
a silver-backed Exchange Traded Fund would soon launch and create
greater investment interest in the metal.  A portion of the
Partnership?s overall gains for the quarter was offset by losses
of approximately 0.4% in global interest rate sector, primarily
during January, from both long and short positions in European,
Australian, and Canadian fixed-income futures as prices moved
without consistent direction amid uncertainty regarding the
interest rate policy of the European Central Bank, the Reserve
Bank of Australia, and the Bank of Canada.  Additional losses of
approximately 0.4% were incurred in the currency sector during
February from short positions in the euro versus the U.S. dollar,
as well as from outright short positions in the U.S. dollar
index, after the U.S. dollar?s value was lifted by expectations
for additional increases in U.S. interest rates.  Further losses
in the currency sector were incurred during March from short
positions in the euro and the Swiss franc relative to the U.S.
dollar as the value of these European currencies moved higher
after the release of generally positive economic data from the
euro-zone reinforced expectations that European interest rates
would continue to rise. The value of the euro then reversed lower
against the U.S. dollar towards the second half of the month amid
negative economic data regarding European consumer spending,
resulting in losses from newly established long positions.
<page> Smaller losses of approximately 0.3% were experienced in
the energy markets from long futures positions in crude oil and
its related products as prices declined during February after
Chinese government authorities announced that China would place
an emphasis on prospecting alternative energy sources in the
future, reports of larger-than-expected supplies from the
International Energy Agency, and mild weather in the U.S.
Northeast.  Further losses in the energy markets were recorded
during March from short positions in crude oil and unleaded
gasoline futures as prices strengthened early in the month on
supply fears fueled by news of geopolitical tensions in Nigeria
and Iran.


For the Quarter Ended March 31, 2005
The Partnership recorded total trading results including interest
income totaling $(461,433), expenses totaling $301,629, and
minority interest of $8,448, resulting in a net loss of $754,614
for the quarter ended March 31, 2005.  The Partnership?s net
asset value per Unit decreased from $1,970.00 at December 31,
2004 to $1,901.50 at March 31, 2005.

The most significant trading losses of approximately 1.6% were
incurred in the currency markets from positions in U.S. dollar
versus various foreign currencies, as well as positions in the
U.S. dollar index as the value of the U.S. dollar moved without
consistent direction throughout most of the quarter.  During
<page> January, short U.S. dollar positions versus the euro and
South African rand resulted in losses after the U.S. dollar?s
value reversed sharply higher amid conflicting economic data,
improvements in U.S. trade deficit data, and speculation for
higher U.S. interest rates.  Additional losses resulted during
January from long positions in the Singapore dollar, versus the
U.S. dollar as the U.S. dollar advanced further due to
expectations that the Chinese government would announce
postponement of Chinese yuan re-valuation for the foreseeable
future.  Short positions in the euro, Singapore dollar, and South
African rand versus the U.S. dollar experienced losses during
February as the U.S. dollar?s value declined amid news of
disappointing U.S. economic data and proposed U.S. dollar
reductions in foreign central bank currency reserves.  Finally,
losses resulted during March from long positions in the euro and
Singapore dollar versus the U.S. dollar, as well as from short
positions in the U.S. dollar index, after the value of the U.S.
dollar reversed sharply higher leading up to and after the
increase in interest rates by the U.S. Federal Reserve.  The
value of the U.S. dollar strengthened further following the
release of a larger-than-expected increase in February consumer
prices.  Within the global stock index futures markets, losses of
approximately 1.2% were recorded in January from long positions
in U.S. equity index futures as prices finished the month lower
amid weak consumer confidence data, concerns regarding U.S.
interest rate policy, and the potential for corporate profit
<page> growth to slow down.  Further losses were experienced
during March from long positions in U.S. equity index futures
after prices moved lower early in the month amid concerns about
the growing U.S. trade deficit, inflation fears, and a surge in
crude oil prices.  Additional losses of approximately 0.1% were
experienced in the agricultural markets, primarily during January
and March, from long futures positions in corn after prices
decreased amid a stronger U.S. dollar and technically-based
selling.  In the global interest rate futures markets, losses of
approximately 0.1% were recorded during February from long
positions in long-term U.S. bond futures as prices declined in
response to positive unemployment data from the U.S. Department
of Labor.  Then, later in the month, further losses were incurred
from long positions as prices moved lower after U.S. Federal
Reserve Chairman Alan Greenspan?s congressional testimony, which
supported Wall Street expectations for more interest rate hikes.
Additional losses were recorded from long positions in European
interest rate futures as prices declined in tandem with the U.S.
fixed-income markets and better-than-expected German economic
data.  During March, losses were recorded from short European
interest rate futures positions as prices increased amid strength
in the euro early in the month as investors feared that continued
strength in the euro could restrict foreign exports.  Prices were
also pushed higher on the outlook that Europe may continue to
maintain a low-interest rate environment and economic concerns
stemming from surging energy prices.  Smaller losses of
<page> approximately 0.1% resulted in the metals sector,
primarily during January, from long futures positions in zinc as
prices weakened on renewed strength in the U.S. dollar, lower
equity prices, and news of a drop in Chinese demand.  A portion
of the Partnership?s overall losses for the quarter was offset by
gains of approximately 0.2% achieved in the energy markets,
primarily during February and March, from long positions in crude
oil and its related products as prices trended higher amid news
of increased demand from China, fears of terror attacks against
production facilities in the Middle East, cold weather in the
Northeastern U.S., and predictions from analysts at Goldman Sachs
that oil prices could reach $105 a barrel.  Further gains were
experienced from long positions in natural gas as prices moved
higher in tandem with crude oil prices.

<page> Item 3.QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT
MARKET RISK

Introduction
The Partnership is a commodity pool engaged primarily in the
speculative trading of futures, forwards, and options.  The
market-sensitive instruments held by the Partnership are acquired
for speculative trading purposes only and, as a result, all or
substantially all of the Partnership?s assets are at risk of
trading loss.  Unlike an operating company, the risk of market-
sensitive instruments is inherent to the primary business
activity of the Partnership.

The futures, forwards, and options traded by the Partnership
involve varying degrees of related market risk.  Market risk is
often dependent upon changes in the level or volatility of
interest rates, exchange rates, and prices of financial
instruments and commodities, factors that result in frequent
changes in the fair value of the Partnership?s open positions,
and consequently in its earnings, whether realized or unrealized,
and cash flow.  Gains and losses on open positions of exchange-
traded futures, forwards, and options are settled daily through
variation margin.  Gains and losses on off-exchange-traded
forward currency contracts are settled upon termination of the
contract, however, the Partnership is required to meet margin
requirements equal to the net unrealized loss on open contracts
in the Partnership accounts with the counterparty, which is
accomplished by daily maintenance of the cash balance in a
<page> custody account held at Morgan Stanley DW for the benefit
of MS & Co.

The Partnership?s total market risk may increase or decrease as
it is influenced by a wide variety of factors, including, but not
limited to, the diversification among the Partnership?s open
positions, the volatility present within the markets, and the
liquidity of the markets.

The face value of the market sector instruments held by the
Partnership is typically many times the applicable margin
requirements.  Margin requirements generally range between 2% and
15% of contract face value.  Additionally, the use of leverage
causes the face value of the market sector instruments held by
the Partnership to typically be many times the total
capitalization of the Partnership.

The Partnership?s past performance is no guarantee of its future
results.  Any attempt to numerically quantify the Partnership?s
market risk is limited by the uncertainty of its speculative
trading.  The Partnership?s speculative trading and use of
leverage may cause future losses and volatility (i.e., ?risk of
ruin?) that far exceed the Partnership?s experience to date
under the ?Partnership?s Value at Risk in Different Market
Sectors? section and significantly exceed the Value at Risk
(?VaR?) tables disclosed.
<page> Limited partners will not be liable for losses exceeding
the current net asset value of their investment.

Quantifying the Partnership?s Trading Value at Risk
The following quantitative disclosures regarding the Partner-
ship?s market risk exposures contain ?forward-looking
statements? within the meaning of the safe harbor from civil
liability provided for such statements by the Private Securities
Litigation Reform Act of 1995 (set forth in Section 27A of the
Securities Act of 1933 and Section 21E of the Securities Exchange
Act of 1934).  All quantitative disclosures in this section are
deemed to be forward-looking statements for purposes of the safe
harbor, except for statements of historical fact.

The Partnership accounts for open positions on the basis of mark to
market accounting principles.  Any loss in the market value of the
Partnership?s open positions is directly reflected in the
Partnership?s earnings and cash flow.

The Partnership?s risk exposure in the market sectors traded by the
Trading Advisor is estimated below in terms of VaR. The Partnership
estimates VaR using a model based upon historical simulation (with
a confidence level of 99%) which involves constructing a
distribution of hypothetical daily changes in the value of a
trading portfolio.  The VaR model takes into account linear
exposures to risk including equity and commodity prices, <page>
interest rates, foreign exchange rates, and correlation among these
variables.  The hypothetical changes in portfolio value are based
on daily percentage changes observed in key market indices or other
market factors (?market risk factors?) to which the portfolio is
sensitive.  The one-day 99% confidence level of the Partnership?s
VaR corresponds to the negative change in portfolio value that,
based on observed market risk factors, would have been exceeded
once in 100 trading days, or one day in 100.  VaR typically does
not represent the worst case outcome.  Demeter uses approximately
four years of daily market data (1,000 observations) and re-values
its portfolio (using delta-gamma approximations) for each of the
historical market moves that occurred over this time period.  This
generates a probability distribution of daily ?simulated profit
and loss? outcomes.  The VaR is the appropriate percentile of this
distribution.  For example, the 99% one-day VaR would represent the
10th worst outcome from Demeter?s simulated profit and loss series.

The Partnership?s VaR computations are based on the risk
representation of the underlying benchmark for each instrument or
contract and do not distinguish between exchange and non-exchange
dealer-based instruments.  They are also not based on exchange
and/or dealer-based maintenance margin requirements.

VaR models, including the Partnership?s, are continually evolving
as trading portfolios become more diverse and modeling techniques
<page> and systems capabilities improve.  Please note that the VaR
model is used to numerically quantify market risk for historic
reporting purposes only and is not utilized by either Demeter or
the Trading Advisor in their daily risk management activities.
Please further note that VaR as described above may not be
comparable to similarly-titled measures used by other entities.

The Partnership?s Value at Risk in Different Market Sectors
The following table indicates the VaR associated with the
Partnership?s open positions as a percentage of total Net Assets by
primary market risk category at March 31, 2006 and 2005. At March
2006 and 2005, the Partnership?s total capitalization was
approximately $16 million and $20 million, respectively.

Primary Market             March 31, 2006        March 31, 2005
Risk Category	  	        Value at Risk        Value at Risk

Equity	(1.56)%	(1.01)%
Interest Rate                   (0.89)		(1.36)
Currency                        (0.09)
	(0.11)
Commodity                       (0.20)
	(0.24)
Aggregate Value at Risk         (2.10)%
	(1.66)%


The VaR for a market category represents the one-day downside
risk for the aggregate exposures associated with this market
category.  The Aggregate Value at Risk listed above represents
the VaR of the Partnership?s open positions across all the market
<page> categories, and is less than the sum of the VaRs for all
such market categories due to the diversification benefit across
asset classes.

Because the business of the Partnership is the speculative trading
of futures, forwards, and options, the composition of its trading
portfolio can change significantly over any given time period, or
even within a single trading day, which could positively or
negatively materially impact market risk as measured by VaR.

The table below supplements the quarter-end VaR set forth above
by presenting the Partnership?s high, low, and average VaR, as a
percentage of total Net Assets for the four quarter-end reporting
periods from April 1, 2005 through March 31, 2006.

Primary Market Risk Category        High      Low      Average
Equity	(1.56)%	(1.17)%	(1.33)%
Interest Rate	(2.89)	(0.89)	(1.51)
Currency	(0.21)	(0.05)	(0.13)
Commodity	(0.27)	(0.12)	(0.20)
Aggregate Value at Risk	(2.86)%	(1.51)%	(2.04)%


Limitations on Value at Risk as an Assessment of Market Risk

VaR models permit estimation of a portfolio?s aggregate market risk
exposure, incorporating a range of varied market risks; reflect
risk reduction due to portfolio diversification or hedging
activities; and can cover a wide range of portfolio assets.  <page>
However, VaR risk measures should be viewed in light of the
methodology?s limitations, which include, but may not be limited to
the following:
*	past changes in market risk factors will not always result in
accurate predictions of the distributions and correlations of
future market movements;
*	changes in portfolio value caused by market movements may differ
from those of the VaR model;
*	VaR results reflect past market fluctuations applied to current
trading positions while future risk depends on future positions;
*	VaR using a one-day time horizon does not fully capture the
market risk of positions that cannot be liquidated or hedged
within one day; and
*	the historical market risk factor data used for VaR estimation
may provide only limited insight into losses that could be
incurred under certain unusual market movements.

In addition, the VaR tables above, as well as the past performance
of the Partnership, give no indication of the Partnership?s
potential ?risk of ruin?.

The VaR tables provided present the results of the Partnership?s
VaR for each of the Partnership?s market risk exposures and on an
aggregate basis at March 31, 2005, and for the four quarter-end
reporting periods from April 1, 2005 through March 31, 2006.  VaR
<page> is not necessarily representative of the Partnership?s
historic risk, nor should it be used to predict the Partnership?s
future financial performance or its ability to manage or monitor
risk.  There can be no assurance that the Partnership?s actual
losses on a particular day will not exceed the VaR amounts
indicated above or that such losses will not occur more than once
in 100 trading days.

Non-Trading Risk
The Partnership has non-trading market risk on its foreign cash
balances.  These balances and any market risk they may represent
are immaterial.

The Partnership also maintains a substantial portion of its
available assets in cash at Morgan Stanley DW; as of March 31,
2006, such amount is equal to approximately 97% of the
Partnership?s net asset value.  A decline in short-term interest
rates would result in a decline in the Partnership?s cash
management income.  This cash flow risk is not considered to be
material.

Materiality, as used throughout this section, is based on an
assessment of reasonably possible market movements and any
associated potential losses, taking into account the leverage,
optionality, and multiplier features of the Partnership?s market-
<page> sensitive instruments, in relation to the Partnership?s
Net Assets.

Qualitative Disclosures Regarding Primary Trading Risk Exposures
The following qualitative disclosures regarding the Partnership?s
market risk exposures ? except for (A) those disclosures that are
statements of historical fact and (B) the descriptions of how the
Partnership manages its primary market risk exposures ? constitute
forward-looking statements within the meaning of Section 27A of the
Securities Act and Section 21E of the Securities Exchange Act. The
Partnership?s primary market risk exposures, as well as the
strategies used and to be used by Demeter and the Trading Advisor
for managing such exposures, are subject to numerous uncertainties,
contingencies and risks, any one of which could cause the actual
results of the Partnership?s risk controls to differ materially
from the objectives of such strategies.  Government interventions,
defaults and expropriations, illiquid markets, the emergence of
dominant fundamental factors, political upheavals, changes in
historical price relationships, an influx of new market
participants, increased regulation, and many other factors could
result in material losses, as well as in material changes to the
risk exposures and the risk management strategies of the
Partnership.  Investors must be prepared to lose all or
substantially all of their investment in the Partnership.

<page> The following were the primary trading risk exposures of the
Partnership at March 31, 2006 by market sector.  It may be
anticipated, however, that these market exposures will vary
materially over time.

Equity.  The largest market exposure of the Partnership at March
31, 2006 was to the global stock index sector, primarily to equity
price risk in the G-7 countries.  The G-7 countries consist of
France, the U.S., Britain, Germany, Japan, Italy, and Canada.  The
stock index futures traded by the Partnership are by law limited to
futures on broadly-based indices.  At March 31, 2006, the
Partnership?s primary exposures were to the S&P 500 (U.S.), DAX
(Germany), NIKKEI 225 (Japan), NASDAQ 100 (U.S.), RUSSELL 2000
(U.S.), and ASX-AOI (Australia) stock indices.  The Partnership is
primarily exposed to the risk of adverse price trends or static
markets in the U.S., European, and Japanese stock indices.  Static
markets would not cause major market changes, but would make it
difficult for the Partnership to avoid trendless price movements,
resulting in numerous small losses.

Interest Rate.  The second largest market exposure of the
Partnership at March 31, 2006 was to the global interest rate
sector.  Exposure was primarily spread across the European, U.S.,
New Zealand, Australian, and Japanese interest rate sectors.
Interest rate movements directly affect the price of the sovereign
bond futures positions held by the Partnership and indirectly
<page> affect the value of its stock index and currency positions.
Interest rate movements in one country, as well as relative
interest rate movements between countries, materially impact the
Partnership?s profitability.  The Partnership?s interest rate
exposure is generally to interest rate fluctuations in the U.S. and
the other G-7 countries interest rates. However, the Partnership
also takes futures positions in the government debt of smaller
countries ? e.g., Australia and New Zealand.  Demeter anticipates
that the G-7 countries interest rates, as well as Australian and
New Zealand interest rates, will remain the primary interest rate
exposures of the Partnership for the foreseeable future.  The
speculative futures positions held by the Partnership range from
short to long-term instruments.  Consequently, changes in short,
medium, or long-term interest rates may have an effect on the
Partnership.

Currency.  At March 31, 2006, the Partnership had market exposure
to the currency sector.  Exposure was to exchange rate
fluctuations, primarily fluctuations which disrupt the historical
pricing relationships between different currencies and currency
pairs.  Interest rate changes, as well as political and general
economic conditions influence these fluctuations.  The Partnership
trades a large number of currencies, including cross-rates - i.e.,
positions between two currencies other than the U.S. dollar.  At
March 31, 2006, the Partnership?s major exposures were to the euro,
Norwegian krone, Australian dollar, New Zealand dollar, <page>
British pound, and Swiss franc currency crosses, as well as to
outright U.S. dollar positions.  Outright positions consist of the
U.S. dollar vs. other currencies.  These other currencies include
major and minor currencies.  Demeter does not anticipate that the
risk associated with the Partnership?s currency trades will change
significantly in the future.

Commodity.
Soft Commodities and Agriculturals.  At March 31, 2006, the
Partnership had market exposure to the markets that comprise
these sectors.  Most of the exposure was to the cotton, corn,
soybeans, wheat, orange juice, live cattle, feeder cattle,
lean hogs, coffee, and cocoa markets.  Supply and demand
inequalities, severe weather disruptions, and market
expectations affect price movements in these markets.

Energy.  At March 31, 2006, the Partnership had market
exposure to the energy sector.  The Partnership?s energy
exposure was primarily to futures contracts in crude oil and
its related products.  Price movements in these markets result
from geopolitical developments, particularly in the Middle
East, as well as weather patterns and other economic
fundamentals. Significant profits and losses, which have been
experienced in the past, are expected to continue to be
experienced in the future.

<page> Metals.	At March 31, 2006, the Partnership had market
exposure in the metals sector.  The Partnership's metals
exposure was to fluctuations in the price of base metals, such
as zinc and copper, and precious metals, such as gold.
Economic forces, supply and demand inequalities, geopolitical
factors, and market expectations influence price movements in
these markets.  The Trading Advisor utilizes the trading
system(s) to take positions when market opportunities develop,
and Demeter anticipates that the Partnership will continue to
do so.

Qualitative Disclosures Regarding Non-Trading Risk Exposure
The following was the only non-trading risk exposure of the
Partnership at March 31, 2006:

Foreign Currency Balances.  The Partnership?s primary
foreign currency balances at March 31, 2006 were in euros,
British pounds, Japanese yen, Australian dollars, Norwegian
krones, Canadian dollars, New Zealand dollars, South African
rand, and Swiss francs. The Partnership controls the non-
trading risk of foreign currency balances by regularly
converting them back into U.S. dollars upon liquidation of
their respective positions.

Qualitative Disclosures Regarding Means of Managing Risk Exposure
The Partnership and the Trading Advisor, separately, attempt to
manage the risk of the Partnership?s open positions in essentially
<page> the same manner in all market categories traded.  Demeter
attempts to manage market exposure by diversifying the
Partnership?s assets among different market sectors and trading
approaches, and by monitoring the performance of the Trading
Advisor daily.  In addition, the Trading Advisor establishes
diversification guidelines, often set in terms of the maximum
margin to be committed to positions in any one market sector or
market-sensitive instrument.

Demeter monitors and controls the risk of the Partnership?s non-
trading instruments cash.  Cash is the only Partnership investment
directed by Demeter, rather than the Trading Advisor.

Item 4.  CONTROLS AND PROCEDURES

(a)	As of the end of the period covered by this quarterly report,
the President and Chief Financial Officer of Demeter, the
general partner of the Partnership, have evaluated the
effectiveness of the Partnership?s disclosure controls and
procedures (as defined in Rules 13a-15(e) and 15d-15(e) of the
Exchange Act), and have judged such controls and procedures to
be effective.

(b)	There have been no material changes during the period
covered by this quarterly report in the Partnership?s
internal control over financial reporting (as defined in
Rules 13a-15(f) and 15d-15(f) of the Exchange Act) or in
<page> other factors that could significantly affect these
controls subsequent to the date of their evaluation.
<page> PART II.  OTHER INFORMATION


Item 1A.  RISK FACTORS

Information regarding risk factors appears in Item 2.
?Management?s Discussion and Analysis of Financial Condition and
Results of Operations? and Item 3. ?Quantitative and Qualitative
Disclosures about Market Risk? of this Form 10-Q.  There have been
no other material changes from the risk factors previously
referenced in the Partnership?s Report on Form 10-K for the fiscal
year ended December 31, 2005.


Item 5.  OTHER INFORMATION
Management.  In connection with the election of new directors to
the Board of Directors of Demeter, the following information
updates the disclosures in the Partnership?s Form 8-K filed on
March 27, 2006 and Form 8-K filed on April 5, 2006:

On April 11, 2006, the National Futures Association approved Mr.
Richard Gueren as a director of Demeter.


Item 6.  EXHIBITS

31.01	Certification of President of Demeter Management
Corporation, the general partner of the Partnership
pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.
31.02	Certification of Chief Financial Officer of Demeter
Management Corporation, the general partner of the
Partnership pursuant to Section 302 of the Sarbanes-Oxley
Act of 2002.

<page>
32.01	Certification of President of Demeter Management
Corporation, the general partner of the Partnership,
pursuant to 18 U.S.C. Section 1350, as adopted pursuant to
Section 906 of the Sarbanes-Oxley Act of 2002.
32.02	Certification of Chief Financial Officer of Demeter
Management Corporation, the general partner of the
Partnership, pursuant to 18 U.S.C. Section 1350, as
adopted pursuant to Section 906 of the Sarbanes-Oxley Act
of 2002.




















<page>





SIGNATURE



Pursuant to the requirements of the Securities Exchange Act of
1934, the Registrant has duly caused this report to be signed on
its behalf by the undersigned thereunto duly authorized.




                      Dean Witter Principal Plus Fund L.P.
                      (Registrant)

                      By:   Demeter Management Corporation
                            (General Partner)

May 15, 2006          By:  /s/Kevin Perry
                              Kevin Perry
                              Chief Financial Officer




The General Partner which signed the above is the only party
authorized to act for the Registrant.  The Registrant has no
principal executive officer, principal financial officer,
controller, or principal accounting officer and has no Board of
Directors.










DEAN WITTER PRINCIPAL PLUS FUND L.P.
NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
6