〔Abstract〕 Objective To investigate the interactional roles and mechanism of the chronic stress during pregnancy(CSDP) and chronic offspring stress(COS) exposures in inducing male offspring depression. Methods The pregnant mice were randomly divided into the normal control group and the chronic stress group. After the offspring were born, male offspring were randomly divided into the normal control+normal control group(NC+NC), the normal control+chronic offspring stress group(NC+COS), the chronic stress during pregnancy+normal control group(CSDP+NC) and the chronic stress during pregnancy+chronic offspring stress group(CSDP+COS). The depression related indices in male offspring mice were detected by forced swim test and elevated plus maze. Pathological changes in hippocampus CA3 area were assessed by Golgi staining and TUNEL staining. The activity of hippocampal mTOR was investigated by using the Western blot to quantitatively detect the expression of mTOR and p-mTOR(Ser2448). Results Chronic stress during pregnancy induced depressive symptoms in male offspring accompanied by neuronal damage and apoptosis in the hippocampus and reduced mTOR activity. The chronic offspring stress ameliorated the depression-like behavior and pathological damage of hippocampal CA3 region in male offspring mice that caused by chronic stress during pregnancy. And the chronic offspring stress elevated mTOR activity. Conclusion Chronic stress during pregnancy induced depressive symptoms in male offspring. The chronic stress could ameliorate the depression-like behavior, neuronal damage and neuronal apoptosis in hippocampal CA3 region of male offspring mice that caused by chronic stress during pregnancy. The chronic offspring stress may improve the depression-like behavior of offspring caused by chronic stress during pregnancy through regulating mTOR activity by corticotropin releasing hormone(CRH).