This study was conducted to examine the effect of small-group game play therapy on the improvement of children's peer relationship skills. The study participants included three children who saw the notice of peer relationship program. Informed consent was submitted for these participants. The small-group game play therapy program was conducted twice a week for 70 minutes. Changes in peer relationship skills were examined using the peer relationship scale for follow-up examinations before and after the implementation of the children's program. In addition, changes in peer relationship skills were examined in free-play situations. The results of this study are as follows: first, small-group game-play therapy was shown to be effective in enhancing children's peer relationship skills; second, small-group game play therapy had a positive effect on the change in children's peer relationship skill response.