In analyzing the process of the forming of a historical phenomenon, the historical geography is important and should be taken into consideration. The aim of this article, based on the historical method of research, is to investigate the role of historical geography in the flourishing of the Hilla School and its effects on the expansion of Shi’a thought in this period. The city of Hilla was built by the Emami Omara of Bani Mazyd sect in the fifth century AH. Dobis I built the city in 419 AH in the rich district so called “Jame'ayn” located in the west bank of the Suru River. Changing the capital of state, Sadaqhat-bin- Mansour divided the region into multiple subdivisions. Hilla, with its highly strategic position, soon became the major center for commerce, agriculture and accumulation of wealth in Iraq. These unique advantages of Hilla encouraged some reputable scholars and literary men of Bani-Mazyd to establish an educated association in the city. During the Abbasid era, especially in Nasser-Ledinellah’s reign, Hilla became a flourishing center for literary and science. Emphasizing education and security development across the territory (from the beginning of Bani Mazyd to the end of Ilkhani age) Ilkhanid also paid special attention to the Shi'a sect. These provided benefits gave Hilla credit as an excellent center of Shi'a jurisprudence school. This strategic situation had a great impact on Shi'a Iran not only ideologically, but also geographically.