The purpose of this paper was to examine the role of group psychotherapy "Mokumoku" with the growth of behavioral and cognition characteristics of the students who participated continuously in the group, by using a longitudinal study with the WISCIII and CBCL. As a result of a longitudinal study of the CBCL for three years, in items beyond the boundary in the first year, there was a significant decrease in the score. In addition, As a result of the WISCIII are indicating that have significantly increased FIQ, FIQ, PO. From these results, the influence of the following three points are suggested. The first point is the experience that is acceptable to others. Second, it's come to terms with the feelings and to share their feelings with others. The third point is that the therapist is for members to encourage understanding of the situation.