The purpose of this investigation was to test the effectiveness of partivipation in exercise on physical sefl-efficacy of obese elementary children. The object of this investigation was 30 students, who were low physical self-efficacy children. there 30 children were randomly assigned experimental-group and contro-group. The exercise program was a 50 minute ond and put into practice three times a week. The pre-test was performed by using Physical Self-Efficacy Scale before they bagan to take part in exercise. After they finished participating exercise for 15 weeks, the post-test was performed by both of two groups. in order to deal with the matericals from both two test, t-test of SPSS program was used, The results were as follows: 1) Te partivipation in exercise for 15 weeks didn\'t have much effect on the perceived phhsical abiility of obese elemenraty school chileren. 2) The partivipation in exercise 15 weeks had positive effect on the physical self-presentation confidence of obese elementary school children. 3) The participation in exercise for 15 weeks had positive effect on the physical self-efficacy of obese elementary school children.