In this study, the effect of group art therapy program on self-reflection of art therapist was investigated. The subjects of this study were 13 beginner art therapists within 3 years of clinical experience. Among them, 7 were grouped into the experimental group and 6 were grouped into the control group. Group art therapy programs were provided to the experimental group for total of 9 sessions for 110 minutes twice a week from July 8 to August 5, 2020. The research tool used the self-reflection scale and the art therapist development level scale and the changes in self-reflection that occurred within the program process were examined step by step. The results are follows: First, the experimental group showed significant improvement in the overall self-reflection scale. Second, positive changes related to self-reflection showed during the group art therapy program. For the art therapist s self-reflection, a group art therapy program that can experience the interaction of container-contained is needed. It also influenced the professional development of art therapists. Therefore, this study confirmed that the group art therapy program has a positive effect on self-reflection of art therapists and is a process of learning meaning from experience.