This study is to verify the effect of group art therapy using food medium on social and self-expression in adults with autism spectrum disorders. The subjects of the study were 24 adults with autism spectrum disorders aged 19 to 45 years old living in S city. To verify the effectiveness of this program, the Mann-Whitney test and Wilcoxon code ranking test were performed using the SPSS 22.0 program. As a result of the study, first, it was confirmed that group art therapy using food medium had a significant effect on the improvement of sociality of adults with autism spectrum disorders. Second, it was found that self-expression was significantly improved. Third, the results of analysis for each program session also showed positive changes and proved the effectiveness. These findings suggest that group art therapy using food medium can be usefully utilized in the clinical field of rehabilitation therapy as a psychological treatment method for adults with autism spectrum disorders.