Hazrat Imam Khomeini (ra) is the first jurisprudent in political history of Shiism who succeeded in establishing a government and restoring theory of guardianship (Velayat-e-Faqih). To this direction, he viewed expedient jurisprudent in a different manner than before and further highlighted its governmental-social aspect than what it had been before. This is while earlier Shiite scholars pointed more to aspect of expediency in religious areas and individual obligations in their writings and the application of this momentum had been ignored in socio-political matters. Hazrat Imam Khomeini (ra) underscoring prophetic biography introduced the expediency as the basic tenet in perpetuating and maintaining the Islamic system; practically speaking, his political conduct represented his commitment to this vital principle in the Islamic community. The article author has tried to analytically and descriptively and based on library research data deal with theory of expediency in thinking and practice of Hazrat Imam Khomeini (ra).