Communication routes are one of the necessary infrastructures for the development of any region and play a major role in its growth. Throughout history, large cities have been formed along important communication routes. Hamedan plain has been on the path of several important roads for a long time and has always been the place of connection between the east and west of Zagros. This writing is based on historical written sources and archaeological evidence to identify the most important communication routes of this cultural field and its impact on political, economic, social and cultural life. Therefore, the current research is one of the first efforts that, with the aim of identifying the key roads of the region, has addressed the effect of this important factor on the prosperity and prosperity of the Hamedan Plain and its settlement centers. The research questions are: What was the location of communication routes of Hamadan plain from the early to middle Islamic centuries? And what is the role of communication routes in the cultural life of the geography of Hamadan during the Seljuq and Ilkhanid periods? This research is based on the method of historical and descriptive research, and the required information has been collected in two ways, documentary and field. The premise of the research indicates that the most important communication route in the region, which played a vital role in the economic, social and cultural structure of the region, was the Great Khorasan Road. This route entered the region from the eastern borders of the Hamedan plain near Bozanjerd village and connected to the western centers of the Iranian plateau from Deh Bozan village in the western border of Hamedan geography. This road is considered the most important communication route between Rey, Holwan and Mesopotamia. During the Islamic period, all exchanges from the city of Rey to the western regions of the country, including the Hamedan plain, were carried out through this route. This situation is also clearly seen in the field of conquests and campaigns of the Mughal patriarchs in the region.