<?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>0007 - Disclosure - Nature and Continuance of Operations</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>From2013-01-01to2013-06-30</ContextID><EntitySchema>http://www.sec.gov/CIK</EntitySchema><EntityValue>0001289441</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>RTBC_DisclosureNatureAndContinuanceOfOperationsAbstract</ElementName><ElementPrefix>RTBC_</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>Nature Of Operations And Continuance:</Label></Row><Row FlagID="0"><Id>2</Id><IsAbstractGroupTitle>false</IsAbstractGroupTitle><LabelSeparator>

</LabelSeparator><Level>2</Level><ElementName>us-gaap_NatureOfOperations</ElementName><ElementPrefix>us-gaap_</ElementPrefix><IsBaseElement>true</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="From2013-01-01to2013-06-30" UnitID=""><Id>1</Id><IsNumeric>false</IsNumeric><IsRatio>false</IsRatio><DisplayZeroAsNone>false</DisplayZeroAsNone><NumericAmount>0</NumericAmount><RoundedNumericAmount>0</RoundedNumericAmount><NonNumbericText>&lt;p&gt;&lt;b&gt;Note 1.&amp;#160; Nature and Continuance of Operations and Going Concern&lt;/b&gt;&lt;/p&gt;

&lt;p&gt;Rotoblock Corporation (&amp;#147;Rotoblock&amp;#148; or the &amp;#147;Company&amp;#148;) was incorporated under the laws of the State of Nevada
on March 22, 2004.&lt;/p&gt;

&lt;p&gt;On March 30, 2004, the Company entered into a Share Exchange Agreement (the &amp;#147;Agreement&amp;#148;) with Rotoblock Inc., a Canadian
corporation incorporated on September 2, 2003, wherein the Company agreed to issue to the stockholders of Rotoblock Inc. 300,000
common shares in exchange for the 144,000 shares that constituted all the issued and outstanding shares of Rotoblock Inc., Effective
March 30, 2004, Rotoblock Inc. completed the reverse acquisition under the Agreement with the Company.&lt;/p&gt;

&lt;p&gt;On November 18, 2011, the Company completed the acquisition of daifuWaste Management Holding Ltd, (&amp;#147;daifu&amp;#148;), a Cayman
Islands company, via Share Exchange Agreement (&amp;#147;Share Exchange Agreement&amp;#148;). Pursuant to the Share Exchange Agreement,
the shareholders of daifu transferred all of the daifu ordinary shares outstanding to the Company in exchange for issuance of
73,801,525 common shares of the Company, par value $0.001 per share, to the daifu shareholders. As at the date of the Share Exchange
Agreement, daifu had 106,356,423 ordinary shares outstanding.&lt;/p&gt;

&lt;p&gt;As at November 18, 2011, the Company had an aggregate of 9,281,160 share purchase warrants and a convertible promissory note
outstanding.&amp;#160; Both instruments remained intact after the Share Exchange Agreement. As a result, daifu shareholders acquired
approximately 81.28% of the Company&amp;#146;s issued and outstanding common stock and common stock equivalents and completed the
reverse acquisition under the Share Exchange Agreement with the Company.&lt;/p&gt;

&lt;p&gt;daifu (&lt;i&gt;formerly named China Healthcare Holdings Limited&lt;/i&gt;), was incorporated in the Cayman Islands on August 1, 2000.&lt;/p&gt;

&lt;p&gt;On June 30, 2008, daifu underwent a reverse merger with its subsidiaries involving an exchange of shares (&amp;#147;Share Exchange&amp;#148;)
between daifu and daifuWaste Management Holding Limited (Samoa) (&amp;#147;daifuWaste Samoa&amp;#148;), daifuWaste Solutions Inc. (&amp;#147;daifuWaste
Solutions&amp;#148;), daifuWaste Investment Limited (&amp;#147;daifuWaste Investment&amp;#148;), Hydroclave China Inc. (&amp;#147;Hydroclave&amp;#148;)
and daifuWaste Investment (Hong Kong) Limited (&amp;#147;daifuWaste HK&amp;#148;).&amp;#160; For financial reporting purposes, this transaction
was classified as a recapitalization of daifuWaste Samoa, daifuWaste Solutions, daifuWaste Investment, Hydroclave and daifuWaste
HK.&amp;#194;&amp;#160; On January 13, 2009, daifuWaste HK acquired Puhua Kangjian Environment Technology (Shenzhen) Limited (&amp;#147;PHKJ&amp;#148;).&lt;/p&gt;

&lt;p&gt;On January 25, 2011, daifuWaste HK invested Renminbi (&amp;#147;RMB&amp;#148;) 1,960,000, 35% of the registered capital to incorporate
a joint venture &amp;#147;Hainanzhou daifu-Luhuan Medical Waste Disposal Co., Ltd.&amp;#148; in the People&amp;#146;s Republic of China (&amp;#147;PRC&amp;#148;)
(Note 7).&lt;/p&gt;

&lt;p&gt;daifu and its subsidiaries are principally engaged in holding medical waste technology, medical waste equipment trading and
holding investments in medical waste treatment centres.&lt;/p&gt;

&lt;p&gt;The Company's interim consolidated financial statements as at June 30, 2013 and for the six month period then ended have been
prepared on a going concern basis, which contemplates the realization of assets and the settlement of liabilities and commitments
in the normal course of business. The Company has net loss of $666,335 for the six month period ended June 30, 2013 (June 30,
2012 net loss of $771,730) and has a working capital deficiency of $3,681,342 at June 30, 2013 (December 31, 2012 - $3,616,773).&lt;/p&gt;

&lt;p&gt;Management cannot provide assurance that the Company will become operating cash flow positive, or raise additional debt and/or equity capital.
However, based on its prior demonstrated ability to raise capital, management believes that the Company's capital resources should
be adequate to continue operating and maintaining its business strategy during the next 12 months. If the Company is unable to
raise additional capital in the near future, due to the Company's liquidity problems, management expects that the Company will
need to curtail operations, liquidate assets, seek additional capital on less favorable terms and/or pursue other remedial measures.
These interim consolidated financial statements do not include any adjustments related to the recoverability and classification
of assets or the amounts and classification of liabilities that might be necessary should the Company be unable to continue as
a going concern.&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>The entire disclosure for the nature of an entity's business, the major products or services it sells or provides and its principal markets, including the locations of those markets. If the entity operates in more than one business, the disclosure also indicates the relative importance of its operations in each business and the basis for the determination (for example, assets, revenues, or earnings).</ElementDefenition><ElementReferences>Reference 1: http://www.xbrl.org/2003/role/presentationRef

 -Publisher FASB

 -Name Accounting Standards Codification

 -Topic 275

 -SubTopic 10

 -Section 50

 -Paragraph 2

 -URI http://asc.fasb.org/extlink&amp;oid=6927468&amp;loc=d3e6003-108592



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