This study was conducted to investigate whether group play therapy using board games is effective in improving the sociality of school-age children. The group play therapy program using board games was conducted twice a week for 6 weeks for a total of 12 sessions, and each session was conducted for 60 minutes. To examine the change, this study compared the pre-and post tests by using the sociality scale, and measured the change in the pro-social behavior found and observed in the peer relations of experimental group children. First, the changes in the sociality of experimental group children were regarded as the sociality scale, and the results were improved after testing. Second, as more sessions were carried out, the number of pro-social behaviors of experimental group children increased steadily and they showed more social enhancement.