Without any doubt ownership and the way of its transfer is a source of many transactions. With the expansion of transactions and their diversity, today ownership has become more complicated creating new kind of contracts which did not have any jurisprudential-legal precedence. Hence elaboration of the characteristics of ownership on the basis of jurisprudential-legal principles can be an index and criterion for validity or invalidity of the newly emerged transactions. There are differences of opinion in Islamic jurisprudence particularly in Imamiyeh jurisprudence about permanency as a characteristic of ownership. But by accepting the temporary ownership and strengthening the theory that denies permanency of
ownership, one can accept the legitimacy of such contracts as the bei'zamani. The present paper is an attempt to review the viewpoints of Imam Khomeini and ritically study the reasons for the invalidity of the said theory and on the other hand besides explaining the referents of temporary ownership in Islamic jurisprudence it refers to the general reasons to prove is legitimacy.