The purpose of this study was to examine the effects of mother-child art therapy on mother-child communication and peer relationships of only child in dual-income families. An experiment group consisting of mother-child pairs for a total of ten people was formed at J Elementary School in Gyeonggi Province in Korea. Total of 12 programs were conducted once a week for 90 minutes from August 2017 to November 2017. The measurement tools used included a mother-child communication scale, BND and a peer relations scale, The pre-post measurement results were analyzed. Consequently, mother-child art therapy showed statistically significant effects on mother-child communication and peer relations, and after analyzing the BND, we could see changes in parent-child positive communication. In addition, positive changes in mother-child communication and peer relations were seen in the process of mother-child art therapy. Therefore, it is clinically valuable to know that mother-child art therapy has been able to promote mother-child communication and improve peer relationships among only child in dual-income families, and we hope that it will be a useful program to help this population in the future based on this research.