One of the clear matters on leadership and Imamat of Ali's reason is Velayat verse. With this lucid document; however, this logic is in doubt by enemies. One of main doubts is to believe on this verse which means leadership of Imam Ali and sent it by Allah in lifelong of the prophet. This is accepted by Sunnies and Shiites which is not proved. Various responses are given to that which is wrong or not true. We decided to give clear and exact answers to these challenges.An abridged response is that the word of leader is not tried to prove Velayat and the right of it. This paper attempts to study this subject by librarical and analytical method to get the best answer the doubt about leadership of Imam Ali in Lifelong of Prophet Muhammad