The purpose for this study was to examine the effects of participating in an inclusive bowling leisure program of extracurricular activities after school on the social competences of junior high school students with and without disabilities. The participants of this study were 7 students with disabilities and 44 students without disabilities who were in inclusive classes of \"S\" junior high school in Incheon. An experimental group was consisted of 22 students without disabilities including 7 students with disabilities, while a control group only 22 students without disabilities. The experimental procedure was composed of pre-test, experimental treatment, and post-test with an inclusive bowling program being implemented for 20 120-minute sessions. The collected quantitative data were analyzed using t-test and qualitative data using content analysis method. The results obtained from this study are summarized as follows: 1. A significant difference was found between the experimental group and the control group on social competences of students without disabilities, showing more improvement in the experimental group. 2. Significant differences were found between the two groups without disabilities on 2 factors of social competences, but not on 3 factors with positive tendencies. 3. Social competences of students with disabilities improved after participating inclusive bowling program. From the qualitative analysis, four themes emerged : (1) social interaction and communication skills (2) problem and positive behavior (3) leisure awareness, (4) leisure skill. In conclusion, the results of this study indicate that the implementation of inclusive bowling program can be a direct and systematic way to improve the social competences of students with and without disabilities.