This study is a case study of sandtray therapy of aggressive child. Mother reported that she is worried about the aggression of the child, such as throwing stuffs out of anger, which have built up by frequent assaults from the father in the growth period. To resolve these internal anger and external aggression of the child, I received a request from the DreamStart Youth Support Project of 00-gun, and conducted a total of 27 sessions of sandtray therapy once a week from April to November 2016. In order to verify the therapeutic effect, HTP, KFD, SCT test were performed before and after, and sandtray therapy process is divided into early, middle, and late stages to describe the changing process of the client. As a result, the sandtray at the beginning of treatment was disturbed and distracted, but gradually became stabilized and arranged as it entered the middle of treatment. In the latter period, sandtray became a child's world, expressing his hopes and desires. Consequently, of aggressive child achieved emotional stability, decreased aggression and increased positive expressive desire through sandtray therapy.