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Coaching is a dynamic and multidimensional process that involves the interaction between the coach, the athlete, the environment and the task, in order to enhance the athlete's performance. Based on the evidence, the coaching method can affect the behavioral aspects of the athlete. In this study, the effectiveness of student-based and coach-based coaching styles on sport self-efficacy and athletic performance of female gymnasts was studied. The research method was quasi-experimental and a pre-test-post-test design was used. The statistical population was female semi-professional gymnasts aged 11-14 in Tehran. The sampling method is one-stage cluster and the research sample was 40 female gymnasts. Variable assessment tools included Sport Self-Efficacy Questionnaire and a researcher-made sports performance Checklist. After the pre-test, the groups performed the athlete- based and coach- based exercises protocol separately for two months and two days a week in one-and-a-half-hour sessions. Covariance analysis was used to test the hypothese. Findings in the post-test stage showed that sport self-efficacy (P <0.001) and athletic performance (P <0.001) of female gymnasts in the student-based group were significantly higher than the coach-based group. It is concluded that student-based exercises style is more effective in increasing Gymnasts' sports self-efficacy and athletic performance compared to coach-based, and coaches are suggested to pay special attention to student-centered exercises in the training program for semi-professional gymnasts.