This study is intended to explore the differences in the level of correlation between participant on social support and social adjustment in connection with Participation of Japanese University student in sports club activities, and clarify the effect of social support on the social adjustment. In order to accomplish the objectives, university students participating in sports club activities of university currently located in Kumamoto, Japan were selected as subjects, and a total of 586 of them were used for final data analysis, using convenience sampling. In order to clarify the correlation among variables based on the collected data, SPSS Window 18.0 was utilized, based on the above methods and processes, the followings results were obtained. First, when the differences in the level of social support and social adjustment were analyzed as to university participants in sports club of general characteristics, which is a social support’s subordinate variable of informative support, it was found to have a significant difference in participation degree (period, time, frequency), while the social adjustment’s subordinate variable of adaptability was found to have a significant difference in participation degree (duration, time, frequency), the impulsivity was founded to have a significant difference in participation gender, grade, period. Second, as for the influence of university participant’s social support on social adjustment, it was found that emotional support factor significantly influences adaptability and impulsivity.