The purpose of this research was to examine how adolescents participation in sports influences the social support of them, to back up empirically the fact that such mutual relation have an effect on the daily removal and easing of the stress, and further, being based upon this, to present the basic data required for the policies related to the adolescents. To examine this research subjects closely in this research the boys` and girls` high school students enrolled in the Office Of Education under the control of Seoul-city as of 2002 have been established as the population and 480 student have been sampled. Among these, excluding those questionnaires which were judged to lack the reliability, the number of the samples used actually for the analysis was total 454 students including the 257 participating students and 197 nonparticipating students in the sports activities. The tool for the data collection is the "Survey questionnaire regarding the relations between the sports participation of the adolescents and the social support and stress", and as a result of the examination of the reliability, the social support α=.90, and the stress α=.94, where high coefficients of the reliability have been derived. For the data analysis the SPSS (Statistical Package for social Science) program has been used in this research, to meet the purpose of this research the covariant analysis, multiple regression analysis and path analyses have been carried out, and the following research results have been derived. First, adolescents participating in the sports activities have higher social support, the lower stress compared with that of the nonparticipating adolescents. Second, among the extents of the adolescents `participation in the sports activities, the participation frequencies have positive relations with the social support and negative relations with the stress. Third, the frequencies of participation is sports activities by the adolescents directly influences the social support, and the social support directly influences the stress. Therefore, the frequencies of participation in sports activities by the adolescents indirectly influence the removal of stress through the social support.