This study purports to investigate the effects of a group art therapy program on self-concept and peer relations of infants or young children. The study subjects are a total of fourteen 5-year kindergarten kids (seven for the experimental group and seven for the control group) from a kindergarten in S-city of Gyeongnam province, who showed low scores on self-concept. The program consisted of 20 sessions of group art therapy for three months, once or twice a week, each session lasting 60 minutes, with in mind five stages of intimacy, self-exploration, self-discovery, self-acceptance, and adaptation in order to enhance their self-concept. Measuring instruments include tests of self-concept and peer relations employed for pre- and post-tests on covariance analysis with qualitative analysis within the sessions. The results are as follows. First, group art therapy is effective in enhancing self-concept of young children. Second, group art therapy has an effect on young children's peer relations. Third, according to the sessional qualitative analysis and behavioral observation, group art therapy helped the children participate in activities with confidence, perform tasks with high concentration, and interact positively with peers. Consequently, it can be claimed that group art therapy works effectively on self-concept and peer relations of young children.