The purpose of this study was to investigate the effects of group expression art therapy natural objects on the self-expression ability and peer relationship of island children. The subjects of this study consisted of six experimental groups and six control groups. The program lasted 16 times, 90 minutes per session for 18 weeks from March to July 2018. Both groups used the Self-Expression Scale and the Peer Relations Index (IPR) after the start and end of the program. As a result, first, the group expression art therapy program natural objects had a positive effect on improving self-expression ability. Second, the group expression art therapy program natural materials was effective in improving peer relations. Taken together, it can be seen that the group expression art therapy program natural objects has a positive effect on the self-expression ability and peer relationship of island children.