This research examined the effects of music therapy on perception change and interpersonal relationship improvement of children with C-PTSD. The subjects of this study were 60 children, diagnosed with complex-post trauma stress disorder C-PTSD by psychiatrists. The research period consisted of 50 minutes per session once a week from July 13 to October 19, 2020, and a total of 10 sessions were conducted. Before and after this program, CPTSD-I was carried out for the subjects and the results were analyzed through paired t-test. The results of this research were as follows: First, the self-perception(p< .05) and the perception of others(p< .01) of the research subjects decreased compared to before experiencing music therapy, and this result was statistically significant. Second, the interpersonal relationships of the research subjects decreased post-test, and the results were statistically significant compared to before experiencing music therapy(p< .01). Therefore, this research obtained the effectiveness of music therapy in changing perceptions and improving interpersonal relationships of children with C-PTSD.