The purpose of this study was to identify the effects of athleriv participation on the social development among the middle school students. Data collected through a questionaire designed for this study consists of exercise participation, frequency, duration, beginning agem career, and difference of the socialication among the students who like the group sport event and the individual sport event. The inventory was administration to 1413 students for data analysis were t-test, ANOVA, and Duncan\'s Grouping test. Based upon the results of the study, the following conclusions were obtained. 1.The more participated to the exercise program, the more effective to their socail development. 2.The earlier participation to the exercise program, the more effective to their socail development. 3.Long participation to the exercise program was more effective to their social development. 4.Lone exercise career was more effective to their social development than the short. 5.We cannot fine any differences between the group sport partivipant and the individual sport partivipant. As the results, we knew that exercise participation of middle school students was good influence on theif social development . So it needs to urge students participate the exercise program for thier physical and social well-being.