This study investigated the underlying mechanism between bullying victimization and depressive symptoms via social trust cross-sectionally and longitudinally among 4,548 early adolescents at T1 and 4,484 adolescents at T2 from rural areas in Guizhou, China. Correlational data showed that all forms of bullying victimization at T1 showed negative correlations with in-group trust at T1 and T2 and generalized trust and depressive symptoms at T1. Both forms of trust were negatively associated with depressive symptoms at both time points. Results of structural equation modeling revealed a significant cross-sectional relationship between T1 bullying victimization and T1 depressive symptoms and that T1 bullying victimization was indirectly related to T1 depressive symptoms through both in-group and generalized social trust at T1. Thus, among students who reported experiencing more bullying, there was a lower level of trust in familiar people and authorities, which mediated their reports of depression. However, social trust did not explain the nonsignificant longitudinal relationship between bullying victimization at T1 and depressive symptoms at T2, potentially due to the lack of control of confounding variables. One implication is the importance of immediate intervention to counteract the tendency to overgeneralize bullying victimization to overall social trust. This study contributes to an empirical understanding of the underlying mechanism between bullying victimization and psychopathology symptoms among early adolescents in rural China.