Mutazilite is one of the significant schools of Islam which has very much contribution to Islam. Mutazilite, which has taken place at the starting of second century of Hegira, has drawn attentions of thinkers and theologians by practicing critical and rational methodology while they are founding their sect principals. Mutazilite School initially has been founded in Basra and then its existence has been felt in Baghdad during Abbasid era. In spite of this Baghdad school basically like-minded with Basra school, there are also much of dissidence between them. Due to some reasons these two schools separated at the end of second century and at the beginning of Hegira. Purpose of this study is detecting these reasons which are caused separating these two Baghdad and Basra schools' of Mutazilite.