摘要:The theories people hold about their own qualities such as abilities are a belief system which is useful in understanding achievement behavior and motivation. Studying self-theories could help us to understand what ability beliefs role is in student performance in physical education. This research aim was to assess the role of students’ self-theories of ability in their performance. For this, a casual was conducted. 50 Iranian male students were participated include 25 entity and 25 incremental theorists. All subjects have been wanted to participate in a three points throw race in basketball. Results of t-test shown that students who had incremental ability belief had better performance compared with students who had entity belief. The findings insist on ability beliefs important role in prediction of students’ performance. Ability beliefs that are felxiable support students’ motivation in difficult tasks relative to rigid and entity strategies. Physical education teachers need encourage incremental beliefs of ability which promot resistance in difficult tasks in physical education.