This research aims to study the Authority of act of Infallible Imam and its illustrations in Jurisprudence through a descriptive-analytic method. Tradition is the second source of legislation and includes the words, actions and writings infallible Imam. Its authority has been proved by the evidence of four including books, tradition, reason and consensus. One aspect of that tradition is the source of discrepancies between the three principal Shiite and Sunni, act of infallible Imam. For this purpose, it has been tried, first, through discussion to prove the infallibility of the Prophet and the Imams and the current tradition in terms of attribution to its owner.