Expediency is among the most important concepts of the Political jurisprudence. Regardless of the primary expedients based on which the divine rules have been issued, expediency has found a new use in the realm of the governmental regulations. Imam Khomeini, in line with the rationalization of the theory of the absolute rule of the jurisprudent, has referred to the central notion of the expediency of the system. Generally, when the religious jurisprudents apply terms such as the disruption of the "system", they mean "social disruption"; however, it seems that by the "expediency of the system", Imam Khomeini refers to the "expediency of the Islamic Government", rather than just the expediency of the social system. Therefore, it might be said that applying the term of expediency with this meaning has been an innovation by the late Imam for the solution of the problems of the Islamic republic government. Although expediency with this meaning is considered as a solution to the problems of the Islamic government, there are theoretical and practical ambiguities in regard with determining the meaning, criteria, and the references for its discernment.