The formation of Achaemenid Empire under Cyrus leadership, its establishment and continuation under his successors, in fact was to shift the empire from Mesopotamia to Iran and to assimilate the Assyria, Babylonia and Egypt empires in an expanded empire under Persians leadership. In its nature, the Achaemenid empire enjoyed the framework composed of the following features and characteristics: having expanded territory with a crowd and consisted of the various ethnics and nations, the dominance of Persian ruling ethnic/tribe over subjects by military power, the formation of consolidated financial organization, having the army composed of the central forces (Persian, Median, Elamid and Scythian) and outlying ones (the forces of other ethnics) settled in empire territory, the delegation of authority to the king while the local powers are subject to him, having relatively the variable frontiers and to manage the internal and external forces, and finally, expending and assemble the necessary grounds for growth and development of all cultures and traditions of subject ethnics and nations. The comparing between the facts of Achaemenid empire and the features and characteristics of one empire suggests that the Persians in the first experiment could establish the empire in which, not only maintained the legacy of former empires but by inspiration of Iranian spirit in its, perplexed the Greek thinkers and on the other hand, arose the grounds of formation of later Iranian empire.