The article discusses the realistic concept of imam and his conditions in society, the way of choosing or appointing him according to the viewpoint of two prominent Shiite and Sunni theologians, on the basis of the descriptive, analytical approach. In this article, a comparison has been made between the concepts used by al-Qadhi al-Baqillani and those used by Allamah al-Hilli, with an evaluation of their opinions. It has been proved that al-Qadhi al-Baqillani's understanding and beliefs differ from those of Allamah al-Hilli and the Twelver Shia consequently; for al-Qadhi al-Baqillani-concerning the way of choosing the imam [by people]-believes in the necessity of the Imam's presence in society; and thus, this necessity would be legal (not rational). Basically, al-Baqillani believes that the topic of Imamate is a jurisprudential (fiqhi) topic. As for Allamah al-Hilli, he believes that the study of Imamate is a theological study, and that the appointment of the Imams is done by God. Based on this, the position of the imam, according to al-Qadhi al-Baqillani and most of Sunni scholars, is an apparent governmental position. According to the Sunnis, in addition to the imam's worldly position, he also undertakes the responsibility of preserving and applying the religion; therefore, they also disagree with the Twelver Shia on the conditions and characteristics of the imam.