This study examined the moderated mediation effect of internal locus of control through BJW-self on the relationship between embitterment and depression. Participants were 254 students aged 18-24 years old who were enrolled in a university located in Gyeonggi. All subjects completed self-assessment inventories about embitterment(Standardization of the Korean Version of the Posttraumatic Embitterment Disorder Self-Rating Scale), BJW(Belief in a Just World Scale: K-BJWS), locus of control(Internality, Powerful others, and Chance: IPC) and depression(PHQ-9). Data collected through online surveys were analyzed by SPSS macro. The results of this study are as follows. First, embitterment has a significant effect on depression. Second, BJW-self mediated the relationship between embitterment and depression Third, the moderation effect of internal locus of control on the relationship between BJW-self and depression was found. Forth, BJW-self mediated the relationship between embitterment and depression, and this mediation was moderated by internal locus of control. moderated mediation effect of internal locus of control was significant only in low locus of control group. These findings suggest that locus of control seems to be an effective intervention for depression and changed cognitive belief caused by embitterment. Based on these findings, the limitations and implication of the study were discussed.