Infallibility of the Imam (a.s.) is one of the foundations of the Imamate in Shi'ism and Shiite scholars have demonstrated its necessity through various proofs and defended it since a long time ago, while this issue has always beencriticized by the opponents.Alusi, a contemporary Sunni interpreter, is among the scholars who disagree with infallibility and has criticized the views of the Twelverson this issue. He believes that infallibility terminates with the seal of the prophecy and only justice and ijtihadsuffice to preservereligion and there is no need for infallibility ofthe Imam. He also believes that there is a contradictionbetween infallibility of the Imam and his occultation as aShi'ite belief. These views of Alusihave been mainly derivedfrom his way of approaching the Imamate and equating the Imamate with caliphate and demoting the Imamate to the rank of ordinary scholars. Some of Alusi’s ideas have been influenced by his predecessors and they have been exploited by the contemporary opponents.Analyzing and evaluating the views of Alusi on rejecting theproofs ofShi'ism,this study explicates the rational proofs offered to demonstrate the necessity of the infallibility of the Imam andestablishhis standing and the status of the Imamate.