The Hormozdgān Battle on 30 Mehr/28 April 224 C.E. is one of the greatest battles in the history of Iran and even the Ancient East. With the demise of Ardavān IV (213224- A.D.), the last king of Parthians, in this war, his warrior rival Ardašir, son of Bābak (240224- A.D) founder of the Sassanids kingdom, called himself ‘King of Kings’, and after conquering the capital of Parthians and other battles with great Parthian families and many local kings who were scattered in Iran, Ardašir was called “King of Kings of Iran”. The Hormozdgān Battle was the beginning of five centuries rule of Sassanids in Iran and was also the beginning of a new period in Iranians-Romans battles. Nevertheless the geographical site of Hormozdgān/ Hormozjān/ Hormozdjān/ Mazdajān plain—that was called the battle field of Ardavān IV and Ardašir son of Bābak by Tabari and others—is not known yet or at least there are different views about it. In this paper, based on a historical method, all these views on geographical site of Hormozdgān plain will be studied and criticized and a new geographical site will be introduced as the site of Hormozdgān Battle.