The purpose of this study is to see if art therapy is effective on improving attentiveness and interpersonal relations of a child with cerebral paralysis. The study subject is an eight year old boy, who was diagnosed as cerebral paralysis of fifth degree when three years old, showing minute difference in the size of hands and feet due to hemiplegia on the right half of his body. The subject has shown behavior of frequent fights or hitting because of negative thoughts on himself and others around, been easily distracted and regressive, and had no good interpersonal relations. Research instruments used in this study are K-CBCL for pretest and posttest to show changes in the levels of problem behavior for the ten K-CBCL subcategories and HTP for pretest and posttest to exhibit psychological changes on attentiveness and interpersonal relationship. According to the data obtained from pretests and posttests of K-CBCL and HTP, art therapy displays an improvement on the subject's attentiveness and interpersonal relations on three K-CBCL subcategories of attentiveness, social prematurity, and aggression. The results from the study are as follows. First, art therapy has a positive effect on the subject's attentiveness. Second, art therapy shows positive changes on the subject's interpersonal relations. Third, the change mode of attentiveness and interpersonal relationship goes with different stages of art therapy.