<?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>0014 - Disclosure - 8. ACCRUED LIQUIDATED DAMAGES</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>From2012-04-01to2013-03-31</ContextID><EntitySchema>http://www.sec.gov/CIK</EntitySchema><EntityValue>0000882291</EntityValue><PeriodDisplayName /><PeriodType>duration</PeriodType><PeriodStartDate>2012-04-01T00:00:00</PeriodStartDate><PeriodEndDate>2013-03-31T00:00:00</PeriodEndDate><Segments /><Scenarios /></contextRef><UPS /><CurrencyCode /><OriginalCurrencyCode /></MCU><CurrencySymbol /><Labels><Label Key="CalendarSupplement" Id="0" Label="12 Months Ended" /><Label Key="Calendar" Id="1" Label="Mar. 31, 2013" /></Labels></Column></Columns><Rows><Row FlagID="0"><Id>1</Id><IsAbstractGroupTitle>true</IsAbstractGroupTitle><LabelSeparator>

</LabelSeparator><Level>1</Level><ElementName>aemd_AccruedLiquidatedDamagesDisclosureTextAbstract</ElementName><ElementPrefix>aemd_</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>Accrued Liquidated Damages</Label></Row><Row FlagID="0"><Id>2</Id><IsAbstractGroupTitle>false</IsAbstractGroupTitle><LabelSeparator>

</LabelSeparator><Level>2</Level><ElementName>aemd_AccruedLiquidatedDamagesDisclosure</ElementName><ElementPrefix>aemd_</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="From2012-04-01to2013-03-31" UnitID=""><Id>1</Id><IsNumeric>false</IsNumeric><IsRatio>false</IsRatio><DisplayZeroAsNone>false</DisplayZeroAsNone><NumericAmount>0</NumericAmount><RoundedNumericAmount>0</RoundedNumericAmount><NonNumbericText>&lt;p style="font: 8pt Times New Roman, Times, Serif; margin: 0"&gt;We account for contingent obligations to make future payments or
otherwise transfer consideration under a registration payment arrangement separately from any related financing transaction agreements,
and any such contingent obligations are recognized only when it is determined that it is probable that we will become obligated
for future payments and the amount, or range of amounts, of such future payments can be reasonably estimated.&lt;/p&gt;

&lt;p style="font: 8pt Times New Roman, Times, Serif; margin: 0; text-indent: 0.5in"&gt;&amp;#160;&lt;/p&gt;

&lt;p style="font: 8pt Times New Roman, Times, Serif; margin: 0"&gt;We have entered into registration payment arrangements in connection
with certain financing arrangements, pursuant to which we raised an approximate aggregate amount of $2,020,000, that require us
to register the shares of common stock underlying the convertible debt and warrants issued in these financing transactions. Under
these agreements we are liable for liquidated damages to the investors if we fail to file and/or maintain effective registration
statements covering the specified underlying shares of common stock as noted below:&lt;/p&gt;

&lt;p style="font: 8pt Times New Roman, Times, Serif; margin: 0; text-indent: 0.5in"&gt;&amp;#160;&lt;/p&gt;

&lt;table cellspacing="0" cellpadding="0" style="width: 100%"&gt;
&lt;tr style="vertical-align: top"&gt;
    &lt;td style="width: 24px"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="width: 24px; font: 8pt Times New Roman, Times, Serif"&gt;&lt;font style="font: 8pt Symbol"&gt;&amp;#183;&lt;/font&gt;&lt;/td&gt;
    &lt;td style="font: 8pt Times New Roman, Times, Serif"&gt;&lt;font style="font-size: 8pt; color: black"&gt;With respect to a $1,000,000 financing agreement &amp;#150; damages accrue at a rate of 1% - 1.5% per month until such time as the underlying shares of common stock would have been eligible for sale under Rule 144.&lt;/font&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;
&lt;p style="font: 8pt Times New Roman, Times, Serif; margin: 0; text-indent: 0.5in"&gt;&amp;#160;&lt;/p&gt;

&lt;table cellspacing="0" cellpadding="0" style="width: 100%"&gt;
&lt;tr style="vertical-align: top"&gt;
    &lt;td style="width: 24px"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="width: 24px; font: 8pt Times New Roman, Times, Serif"&gt;&lt;font style="font: 8pt Symbol"&gt;&amp;#183;&lt;/font&gt;&lt;/td&gt;
    &lt;td style="font: 8pt Times New Roman, Times, Serif"&gt;&lt;font style="font-size: 8pt; color: black"&gt;With respect to financing agreements totaling $715,000 &amp;#150; damages accruing at a rate of 2% per month, subject to an aggregate maximum liquidated damages amount of $150,000.&lt;/font&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;
&lt;p style="font: 8pt Times New Roman, Times, Serif; margin: 0; text-indent: 0.5in"&gt;&amp;#160;&lt;/p&gt;

&lt;table cellspacing="0" cellpadding="0" style="width: 100%"&gt;
&lt;tr style="vertical-align: top"&gt;
    &lt;td style="width: 24px"&gt;&amp;#160;&lt;/td&gt;
    &lt;td style="width: 24px; font: 8pt Times New Roman, Times, Serif"&gt;&lt;font style="font: 8pt Symbol"&gt;&amp;#183;&lt;/font&gt;&lt;/td&gt;
    &lt;td style="font: 8pt Times New Roman, Times, Serif"&gt;&lt;font style="font-size: 8pt; color: black"&gt;With respect to equity investments totaling $305,000 &amp;#150; damages accruing at a rate of 2% per month until the expiration dates of warrants issued in connection with this financing, which range from December 31,2010 through February 8, 2011 and are payable in common stock.&lt;/font&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;
&lt;p style="font: 8pt Times New Roman, Times, Serif; margin: 0; text-indent: 0.5in"&gt;&amp;#160;&lt;/p&gt;

&lt;p style="font: 8pt Times New Roman, Times, Serif; margin: 0"&gt;Since we have either failed to file, or failed to maintain the registration
obligations under these agreements, as of March 31, 2013, we have accrued estimated aggregate liquidated damages of $437,800 in
connection with the liquidated damage provisions of these agreements, which we believe represents our maximum exposure under these
provisions.&amp;#160;&amp;#160;Accordingly, we do not expect to accrue any further liquidated damages in connection with these agreements.&amp;#160;&amp;#160;The
actual amount of liquidated damages paid, if any, may differ from our estimates as it is our intention to negotiate with the investors
the settlement of liquidated damages due and, as such, the ultimate amounts we may actually pay may be less than the amount currently
accrued.&lt;/p&gt;</NonNumbericText><FootnoteIndexer /><CurrencyCode /><CurrencySymbol /><IsIndependantCurrency>false</IsIndependantCurrency><ShowCurrencySymbol>false</ShowCurrencySymbol><DisplayDateInUSFormat>false</DisplayDateInUSFormat></Cell></Cells><ElementDataType>nonnum:textBlockItemType</ElementDataType><SimpleDataType>na</SimpleDataType><ElementDefenition>No authoritative reference available.</ElementDefenition><ElementReferences>No definition available.</ElementReferences><IsTotalLabel>false</IsTotalLabel><UnitID>0</UnitID><Label>ACCRUED LIQUIDATED DAMAGES</Label></Row></Rows><Footnotes /><IsEquityReport>false</IsEquityReport><ReportName>8. ACCRUED LIQUIDATED DAMAGES</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://aethlonmedical.com/role/AccruedLiquidatedDamages</RoleURI><NumberOfCols>1</NumberOfCols><NumberOfRows>2</NumberOfRows></InstanceReport>
