During the seventh century, due to various political, social, and cultural factors such as the activities of Shi'ite scholars, the Sufis and the social movement of Futuwa, political turmoil, and Mongol religious tolerance the Imami Shi'ism expanded. The function of the Shi'a ministers in the court of the Abbasid caliphate is one of these factors. By a descriptive-analytical method, this article seeks to give a brief overview of the life and career of Shia ministers in the 7th century AH, and examine their role in expansion of Shi’ ism. The findings of this study show that during this period, the Abbasid caliph al-Naser le-Din al-Allah (r. 575-622 AH), for religious unity, appointed some of the Shi'ites to the ministry. Using the opportunity, Shi'ite ministers also played a prominent role on the strengthening the cultural and social development of Shi'ites and promoting their beliefs in the caliphate territory through various manners such as assigning office positions to their co-religions, reconstruction of the tombs of the Imams and, trusteeship of Mustansaria School.