This study was conducted to find the effect of the directed sand-tray play therapy on the self-concept improvement in multi-cultural family children. Subjects are three children of multi-cultural family at age 10 to 11 were selected because of the low self-concept points. The program was carried out 12 times, twice a week, 60 minutes per session, The change of self-concept in multi-cultural family children was evaluated by comparing with self-concept scores before/after the program and changes in verbal/free-play activity were analyzed by self-expression scale/the play-activity observation sheet. The results of this study are as follows: First, the directed sand-tray play therapy improves the self-concept points of multi-cultural family children. Second, during the directed sand-tray play therapy, positive linguistic expression has increased while negative expressions decreased. Third, through the directed sand-tray play therapy, the free-play pattern of multi-cultural family children has changed from playing alone into group-play. As this study includes only a few cases, conclusions have limitations to generalize. However, it has shown that the directed sand-tray play therapy can improve the self-concept of multi-cultural family children.