The movement and migration of Shiites to other lands outside the Arabian Peninsula took place following events such as the support of rulers of various regions, the strictness of Umayyad and Abbasid rulers, etc., and caused the spread of Shiite thought in other regions such as Iran and Iraq. Of course, their differences - the Shiites - with the Umayyad and Abbasid caliphs intensified this process. The region that we know today as Lorestan is one of the regions that has always been a base and center of Shiism, and today the residents of this region are all followers of the Shiite religion. This article, with a brief reference to the historical background of Lorestan, discusses the influence of Shiism and its spread in this geographical region of Iran and seeks to find an answer to the question of what factors influenced the acceptance of Shiism and the ways in which it spread in Lorestan? The results of the studies indicate that the migration of Alawites, the increase in the arrival of Imamzadeh and Sadat to various regions of Iran, including Lorestan, following the migration of Imam Reza (AS), the proximity of Lorestan to the Shiite areas of Iraq, the migration of some Arab groups, the specific geographical conditions of the region, and in the following years, the Mongol domination of Islamic lands were among the reasons for the spread of Shiism in Lorestan.