This research is trying to accomplish a comparative study on the theoretical basis of Farr–e Izadi (divine charisma) and Zell-allah (shadow of God) based on historical texts and narratives of Muslim scholars and to answer the questions about their similarities and differences and about is it possible to assume Zell-allah concept as a continuation of Farr–e Izadi? In contrary with the commonly thought which suppose these two concepts as a same kind, the main hypothesis of this paper is that Farr–e Izadi (divine charisma) and zell-allah (shadow of God) concepts despite some commonalities have important distinctions and differences.The results of this research which have been achieved by application of historical explanation and comparative method show that these two concepts belong to two cultural systems of history of Iran which each of these two concepts has have the possibility of emergence in its especial conditions of its own period. Thus Farr–e Izadi (divine charisma) should be comprehended in the context of political culture of Kingship in ancient Iran and zell-allah (shadow of God) should be comprehended in the context of the Sultanate system of Islamic period.