The peace treaty between Imam Hasan (a) and Muawiya is among the main events of early period of Islam which took place after the death of Uthman in 35 (A.H), when rallies were formed by followers of Uthman in seeking his revenge in Sham and Iraq. (Brief History) But the role of Gharat battles on the peace treaty is not explained yet, although the importance of other factors on this event is not ignored. (Problem) It is clear that no research has been done on this issue, then the raised question here is: Did Gharat battles have consequences in facilitation of the peace treaty between Imam Hasan (a) and Muawiya? (Question) It is assumed the number of Gharat battles have made Iraqi people worried which along with their internal problems led to their decline. As a result, these battles and constant pressure in the six-month caliphate of Imam and its consequences are among the main reasons behind the peace treaty between Imam Hasan (a) and Muawiya. (Hypothesis) The present paper tries to explain the role of Gharat battles on the peace treaty (Purpose) by means of collecting relative data and applying a descriptive – analytical approach. (Methodology) The strategies of Muawiya in Gharat battles along with vulgar behavior of his official agents disordered the balance between martial groups and people of Iraq which led to the downfall and confusion among people. (Finding).