ThePurpose ofThis Article is toAssess the Validityof Mortgageof Debt in Imamie Jurisprudence and Iran Law with a Descriptive andAnalytical Method.According to the FamousView in Imamie JurisprudenceCertain Goodsof Mortgage andthe Possibilityof a Delivery is aValidity Condition.Therefore, Mortgageof Debt isNot Valid.because Debt isNot Tangibleand Deliverable.The Iran Legislator in CivilLaw has Explicitly Ruled inValidity of Mortgage of Debt by Virtue of Article774 as a Consequence of the Jurists. Debts like Demands and Commercial Documents Although, as a Rule,These Properties Like CertainGoods Are Not Deliverable by Mortgages but in Most Cases, It is Possible Customary andSpiritual Deliver of This Kind of property in order to Maintain the Rights of the Mortgagor. And Void of it is far from the Logic and Needs of the Commercial and Economic. Especially as the Research shows in this Article, In Imamie Jurisprudence, there is no Consensus between the Jurists on the Necessity of Delivery. in Iran Law the Legislator in Many Cases Such as Commercial and Bank Laws, Believes Invalidity of Mortgage of Debt and Somehow Reverted Invalidation Verdict in the Civil Code. Therefore, it is Suggested That the Legislator, While Modifying the Civil Code, will Provide the Basis for Accepting All That is Financially Valuable as Mortgage.