<?xml version="1.0" encoding="us-ascii"?><InstanceReport xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"><Version>2.4.0.8</Version><ReportLongName>114 - Disclosure - ASSET PURCHASE</ReportLongName><DisplayLabelColumn>true</DisplayLabelColumn><ShowElementNames>false</ShowElementNames><RoundingOption /><HasEmbeddedReports>false</HasEmbeddedReports><Columns><Column FlagID="0"><Id>1</Id><IsAbstractGroupTitle>false</IsAbstractGroupTitle><LabelSeparator>

</LabelSeparator><CurrencyCode /><FootnoteIndexer /><hasSegments>false</hasSegments><hasScenarios>false</hasScenarios><MCU><KeyName /><CurrencySymbol /><contextRef><ContextID>P01_01_2013To06_30_2013</ContextID><EntitySchema>http://www.sec.gov/CIK</EntitySchema><EntityValue>0001166708</EntityValue><PeriodDisplayName /><PeriodType>duration</PeriodType><PeriodStartDate>2013-01-01T00:00:00</PeriodStartDate><PeriodEndDate>2013-06-30T00:00:00</PeriodEndDate><Segments /><Scenarios /></contextRef><UPS /><CurrencyCode /><OriginalCurrencyCode /></MCU><CurrencySymbol /><Labels><Label Key="CalendarSupplement" Id="0" Label="6 Months Ended" /><Label Key="Calendar" Id="1" Label="Jun. 30, 2013" /></Labels></Column></Columns><Rows><Row FlagID="0"><Id>1</Id><IsAbstractGroupTitle>true</IsAbstractGroupTitle><LabelSeparator>

</LabelSeparator><Level>1</Level><ElementName>bwmgd_AssetPurchaseAbstract</ElementName><ElementPrefix>bwmgd_</ElementPrefix><IsBaseElement>false</IsBaseElement><BalanceType>na</BalanceType><PeriodType>duration</PeriodType><IsReportTitle>false</IsReportTitle><IsSegmentTitle>false</IsSegmentTitle><IsCalendarTitle>false</IsCalendarTitle><IsEquityPrevioslyReportedAsRow>false</IsEquityPrevioslyReportedAsRow><IsEquityAdjustmentRow>false</IsEquityAdjustmentRow><IsBeginningBalance>false</IsBeginningBalance><IsEndingBalance>false</IsEndingBalance><IsReverseSign>false</IsReverseSign><FootnoteIndexer /><Cells><Cell FlagID="0" ContextID="" UnitID=""><Id>1</Id><IsNumeric>false</IsNumeric><IsRatio>false</IsRatio><DisplayZeroAsNone>false</DisplayZeroAsNone><NumericAmount>0</NumericAmount><RoundedNumericAmount>0</RoundedNumericAmount><NonNumbericText /><FootnoteIndexer /><CurrencyCode /><CurrencySymbol /><IsIndependantCurrency>false</IsIndependantCurrency><ShowCurrencySymbol>false</ShowCurrencySymbol><DisplayDateInUSFormat>false</DisplayDateInUSFormat></Cell></Cells><ElementDataType>xbrli:stringItemType</ElementDataType><SimpleDataType>string</SimpleDataType><IsTotalLabel>false</IsTotalLabel><UnitID>0</UnitID><Label>Asset Purchase [Abstract]</Label></Row><Row FlagID="0"><Id>2</Id><IsAbstractGroupTitle>false</IsAbstractGroupTitle><LabelSeparator>

</LabelSeparator><Level>2</Level><ElementName>bwmgd_AssetPurchaseTextBlock</ElementName><ElementPrefix>bwmgd_</ElementPrefix><IsBaseElement>false</IsBaseElement><BalanceType>na</BalanceType><PeriodType>duration</PeriodType><IsReportTitle>false</IsReportTitle><IsSegmentTitle>false</IsSegmentTitle><IsCalendarTitle>false</IsCalendarTitle><IsEquityPrevioslyReportedAsRow>false</IsEquityPrevioslyReportedAsRow><IsEquityAdjustmentRow>false</IsEquityAdjustmentRow><IsBeginningBalance>false</IsBeginningBalance><IsEndingBalance>false</IsEndingBalance><IsReverseSign>false</IsReverseSign><PreferredLabelRole>verboseLabel</PreferredLabelRole><FootnoteIndexer /><Cells><Cell FlagID="0" ContextID="P01_01_2013To06_30_2013" UnitID=""><Id>1</Id><IsNumeric>false</IsNumeric><IsRatio>false</IsRatio><DisplayZeroAsNone>false</DisplayZeroAsNone><NumericAmount>0</NumericAmount><RoundedNumericAmount>0</RoundedNumericAmount><NonNumbericText>              &lt;table border="0" style="clear:both;width:100%; table-layout:fixed;"&gt;  &lt;tr&gt;  &lt;td&gt;&lt;/td&gt;  &lt;/tr&gt;  &lt;/table&gt;    &lt;div style="clear:both; FONT-FAMILY:Times New Roman;FONT-SIZE: 10pt;MARGIN: 0pt 0px; FONT: 10pt Times New Roman, Times, Serif "&gt;  &lt;div style="clear:both; FONT-FAMILY:Times New Roman;FONT-SIZE: 10pt"&gt;  &lt;table style="clear:both;MARGIN-TOP: 0pt; FONT: 10pt Times New Roman, Times, Serif; MARGIN-BOTTOM: 0pt"   cellspacing="0" cellpadding="0" width="100%"&gt;  &lt;tr style="VERTICAL-ALIGN: top"&gt;  &lt;td style="WIDTH: 0.25in"&gt;  &lt;div&gt;8.&lt;/div&gt;  &lt;/td&gt;  &lt;td style="TEXT-ALIGN: justify"&gt;  &lt;div&gt;&lt;u&gt;ASSET PURCHASE&lt;/u&gt;&lt;/div&gt;  &lt;/td&gt;  &lt;/tr&gt;  &lt;/table&gt;  &lt;/div&gt;    &lt;div style="clear:both; FONT-FAMILY:Times New Roman;FONT-SIZE: 10pt;TEXT-ALIGN: justify; MARGIN: 0pt 0px 0pt 0.25in; FONT: 10pt Times New Roman, Times, Serif"&gt;  &amp;#160;&lt;/div&gt;    &lt;div style="clear:both; FONT-FAMILY:Times New Roman;FONT-SIZE: 10pt;TEXT-ALIGN: justify; MARGIN: 0pt 0px 0pt 0.25in; FONT: 10pt Times New Roman, Times, Serif"&gt;  On February 3, 2012, the Company entered into an asset purchase  agreement with Florida Dive Industries, Inc.  (&amp;#8220;Seller&amp;#8221;). On March 5, 2012, the same parties executed  an amendment (&amp;#8220;Amendment&amp;#8221;) to the agreement  (collectively, the &amp;#8220;Agreement&amp;#8221;). Under the terms of the  Agreement, the Company acquired certain diving and related  inventory, and Seller provided a three year non-compete agreement  within a 10-mile wide radius. In addition, the Company assumed a  commercial lease obligation for a retail dive store in Boca Raton,  Florida beginning in April 1, 2012. The lease is automatically  renewable on an annual basis through &lt;font style=" FONT-SIZE: 10pt"&gt;May 31, 2014&lt;/font&gt;, with &lt;font style=" FONT-SIZE: 10pt"&gt;90&lt;/font&gt; days written notice assuming the  Lessee is in compliance with all terms of the lease. The lease  amount is base rental plus an allocated amount of common areas  maintenance (&amp;#8216;CAM&amp;#8221;). &lt;font style=" "&gt;Base rental  increases annually by the greater of 5% or the annual consumer  price index.&lt;/font&gt; The current monthly rental including CAM at the  time of assignment is approximately $&lt;font style=" FONT-SIZE: 10pt"&gt;3,200&lt;/font&gt;.&lt;/div&gt;    &lt;div style="clear:both; FONT-FAMILY:Times New Roman;FONT-SIZE: 10pt;TEXT-ALIGN: justify; MARGIN: 0pt 0px 0pt 0.25in; FONT: 10pt Times New Roman, Times, Serif"&gt;  &amp;#160;&lt;/div&gt;    &lt;div style="clear:both; FONT-FAMILY:Times New Roman;FONT-SIZE: 10pt;TEXT-ALIGN: justify; MARGIN: 0pt 0px 0pt 0.25in; FONT: 10pt Times New Roman, Times, Serif"&gt;  As a purchase price, the Company agreed to pay Seller, on a monthly  basis, beginning April 1, 2012, and thereafter until May 13, 2013,  in equal payments, the total cash purchase price of $&lt;font style=" FONT-SIZE: 10pt"&gt;22,500&lt;/font&gt;. In addition, the Company issued  Seller &lt;font style=" FONT-SIZE: 10pt"&gt;1,630&lt;/font&gt; restricted  shares of&amp;#160;stocknas part of the purchase price as provided for  in the Amendment, or $59,400.. Both the restricted stock and the  monthly payments due Seller were maintained in an escrow account  for six months as a purchase price holdback for contingent  liabilities not otherwise settled by Seller. If such items  including rent and any building or zoning code violations had not  been paid by Seller during this period, the Company would have  settled said liabilities with the purchase price holdback. On  October 26, 2012, the Company issued the seller the &lt;font style=" FONT-SIZE: 10pt"&gt;1,630&lt;/font&gt; shares previously heldback. As of  June 30, 2013, the Company had paid Seller $&lt;font style=" FONT-SIZE: 10pt"&gt;9,643&lt;/font&gt; toward the $22,500 cash purchase  price leaving a balance of $&lt;font style=" FONT-SIZE: 10pt"&gt;12,857&lt;/font&gt;.&lt;/div&gt;    &lt;div style="clear:both; FONT-FAMILY:Times New Roman;FONT-SIZE: 10pt;TEXT-ALIGN: justify; MARGIN: 0pt 0px 0pt 0.25in; FONT: 10pt Times New Roman, Times, Serif"&gt;  &amp;#160;&lt;/div&gt;    &lt;div style="clear:both; FONT-FAMILY:Times New Roman;FONT-SIZE: 10pt;TEXT-ALIGN: justify; MARGIN: 0pt 0px 0pt 0.25in; FONT: 10pt Times New Roman, Times, Serif"&gt;  On May 31, 2013, the Company closed the dive store and vacated the  premises. The Company forfeited its deposit with the landlord for  failure to provide 90 days&amp;#8217; written notice of intent to  vacate. As a result, the Company wrote-off as other expense the  amount on deposit with the landlord, or $&lt;font style=" FONT-SIZE: 10pt"&gt;3,200&lt;/font&gt;. However, the Company believes  there is still a possibility the deposit will be refunded per  negotiations with the landlord. If this occurs, the Company will  recognize as other income in the subsequent period in which the  deposit is refunded.&lt;/div&gt;  &lt;/div&gt;        </NonNumbericText><FootnoteIndexer /><CurrencyCode /><CurrencySymbol /><IsIndependantCurrency>false</IsIndependantCurrency><ShowCurrencySymbol>false</ShowCurrencySymbol><DisplayDateInUSFormat>false</DisplayDateInUSFormat></Cell></Cells><ElementDataType>nonnum:textBlockItemType</ElementDataType><SimpleDataType>na</SimpleDataType><ElementDefenition>The entire disclosure relating to the asset purchase</ElementDefenition><ElementReferences>No definition available.</ElementReferences><IsTotalLabel>false</IsTotalLabel><UnitID>0</UnitID><Label>Asset Purchase [Text Block]</Label></Row></Rows><Footnotes /><IsEquityReport>false</IsEquityReport><ReportName>ASSET PURCHASE</ReportName><MonetaryRoundingLevel>UnKnown</MonetaryRoundingLevel><SharesRoundingLevel>UnKnown</SharesRoundingLevel><PerShareRoundingLevel>UnKnown</PerShareRoundingLevel><ExchangeRateRoundingLevel>UnKnown</ExchangeRateRoundingLevel><HasCustomUnits>true</HasCustomUnits><IsEmbedReport>false</IsEmbedReport><IsMultiCurrency>false</IsMultiCurrency><ReportType>Sheet</ReportType><RoleURI>http://www.browniesmarinegroup.com/role/AssetPurchase</RoleURI><NumberOfCols>1</NumberOfCols><NumberOfRows>2</NumberOfRows></InstanceReport>
