The purpose of this study is to investigate the effect of art therapy on middle school students' aggression and self-esteem for aggressive middle school students residing in welfare facilities. As for the study subject, male middle school student was selected, who resided in a childcare center located in P City and was so aggressive and hard to control his feelings that his anger exploded frequently. The program was conducted a total of 14 times, for 60 minutes once a week. To find out the change of aggression and self-esteem, A measurement tool was used for measurement and analysis, Aggression measure and Selfesteem measure and K-HTP examination. Moreover, the subject's work and behaviors during each session were observed to record his change of behavior. The results of this study are as follows: Firstly, the aggression was found to decrease by comparing the pretest and posttest of the aggression test. Secondly, in the self-esteem test, the subject showed 1 point higher in the posttest, which indicates there was not large change. But differences between the pretest and posttest of K-HTP showed that the subject showed improvements in self-esteem. Accordingly, there was no large change found in Self-esteem Scale, but this study found out that art therapy had positive effect on the improvement of self-esteem and the decrease of aggression of a middle school student residing in welfare facilities.