Although well-established literature has indicated the burden of mental health among victims after the Wenchuan earthquake, no research has focused on the mental health of mothers and their children who experienced the earthquake and were pregnant during or shortly after it. This study investigates the relationship between maternal trauma exposure (TE) and children's depressive symptoms after the Wenchuan earthquake and explores the risk and protective factors underlying this relationship. A sample of 547 mother-child dyads, in which the mother experienced the Wenchuan earthquake, was used to assess maternal depressive symptoms, maternal TE, children's depressive symptoms, children's perceived impact of the earthquake and maternal posttraumatic growth (PTG). The results showed that maternal TE had two significant one-step indirect associations with children's depressive symptoms (through children's perceived impact of the earthquake and maternal PTG) and one two-step indirect association with children's depressive symptoms (through maternal depressive symptoms via children's perceived impact of the earthquake). The results indicated that maternal depressive symptoms, children's perceived impact of the earthquake and maternal PTG mediated the association between maternal TE and children's depressive symptoms. These findings highlight the importance of mothers in supporting the mental health of these children. Maternal depressive symptoms and PTG, two posttraumatic outcomes, played positive and negative roles in the intergenerational transmission of trauma. Thus, post-disaster interventions should reduce the maternal transmission of trauma-related information and improve maternal PTG to support children's mental health.