This research has been developed with the aim of comparing the effectiveness of schema therapy and cognitive behavior therapy on the self-efficacy of lifestyle related to weight and weight loss .In order to achieve this goal, through a semi-experimental design with a pretest and a posttest , all female students of Bu Ali Sina university whose index of body mass was between 25 and 35 were interviewed ,and then 30 of them who had the criteria of participating in schema therapy and cognitive behavior therapy sessions were chosen as the available samples and then were put randomly  into three groups (two experimental groups and a control group).The first group received schema therapy for 10 one-hour sessions, the second group received cognitive behavior therapy for 10 one-hour sessions and the third group as the control group received no intervention. The gathered data were analyzed through covariance analysis. The results showed that both schema therapy and cognitive behavior therapy had a positive effect on the improvement of the self-efficacy of lifestyle related to weight gain and weight loss. However, the efficacy of the schema therapy was more than the efficacy of the cognitive behavior therapy. Furthermore, no change occurred in the control group during the process of assessment. Generally, both schema therapy and cognitive behavior therapy had an effect on the increase of the sense of control over areas of lifestyle related to weight and weight control.