The purpose of this was to investigate the relationship institutionalized childrens ego-identities and internal locus of control to behavior problems. The subjects were 119 5th and 6th graders(58 boys, 61 girls) who were institutionalized in Seoul. The major findings of this study were as follows: 1) The institutionalized childrens internal locus of control and ego-identity were not significant difference in gender, reason for entering the institution and duration in he institution. The institutionalized childrens internal locus of control was significantly related to their ego-identity. The more internal locus of control, the higher ego-identity. 2) The institutionalized childrens behavior problems were not significant difference in gender and duration in the institution, but were significant difference reason for entering the institution. The children who were institutionalized by parents absence were more likely to have behavior problems than children by economic problem or marital conflict. The institutionalized childrens behavior problems were significantly related to their ego-identities and internal locus of control. The less internal locus of control, the more behavior problems, and the less ego-identities, the more behavior problems.