This study was conducted with the aim of responding to cyberbullying, a new type of school violence. To this end, the relationship between adolescents’ use of smart media and cyberbullying was examined, and whether aggressiveness had a mediating effect. Through this study, we will provide an empirical basis for preparing interventions that can mediate adolescents’ cyberbullying. To conduct this study, a questionnaire of 555 students enrolled in middle school was analyzed using SPSS and AMOS statistical programs. The main results of this study are as follows. First, it was found that adolescents’ use of smart media had a positive (+) effect on aggression. Second, aggression was found to have a positive (+) effect on adolescents’ cyberbullying. Third, it was found that youth’s use of smart media had a positive (+) effect on cyberbullying. Fourth, aggression was found to have a mediating effect on youth’s use of smart media and cyber bullying. Based on these findings, a social welfare intervention plan was proposed to prevent and reduce adolescents’ cyberbullying.