The aim of present study was to investigate the effectiveness of Applied Behavioral Analysis on social skills development of children with autism spectrum disorder. The study was a quasi-experimental research with a pre-test-post-test-follow-up with control group. A sample of 30 children with the diagnosis of autism spectrum disorder in Kermanshah is selected using available sampling method, who were randomly assigned to experiment and control groups of 15. The experiment group received social skills training program for 8 months using applied behavioral analysis method. The research tool was Winelend Social Growth Scale and the data were analyzed using SPSS19. The findings showed that there is a significant difference between the pre-test and post-test scores (eight month intervals) and the follow-up (one month interval) of the experiment group in social skill growth (p<0/01). The results of this study show that the therapeutic method of applied behavioral analysis is effective for improving the social skills of children with autism spectrum disorder. Therefore, the implementation of this therapeutic approach is recommended along with the rest of the treatments.