The current study is aimed to understand aggressive behavior of school bullying and violence so as to explore relationships among student\'s gender, self-concept, and interpersonal relations. First, hierarchical multiple regression analyses were conducted to determine the extent to which aggressive behavior can be explained by student\'s gender, self-concept, and interpersonal relations. The result showed that student\'s gender, self-concept, and interpersonal relations were significant predictors to aggressive behavior, with 9% of aggressive behavior variance being explained. Second, since interaction effect of student\'s gender and one of other predictors was examined, an interaction term between student\'s gender and social self-concept was significant. That is, female students who had positive social self-concept were more likely to involve in aggressive behavior than those who had negative social self-concept. This was not the case for male students. Third, structural equal modeling was carried out to explore the relationship of self-concept, interpersonal relations, and aggressive behavior. While a mediational model as hypothetical one was created, integrative and independent models served as alternative ones. The mediation model posits that interpersonal relations mediate the linkage between self-concept and aggressive behavior. The independent model hypothesizes that self-concept and interpersonal relations impact aggressive behavior independently. The integrative model combined two models, independent and mediation ones. The LISREL output showed that the mediational model was better than the other alternative models. The model fits did not differ in male and female students.