Objective To observe the effects of chronic emotional stress on the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) and malonialdehyde (MDA) level in female rats’ brain. Methods The rats were randomly divided into 4 groups: normal control group (group N), emotional stress group (group E), emotional stress + pregnancy group (group E+P) and regularly drinking group (group R). Emotional stress in rats was induced by training rats with empty drinking bottles. Having been finished the stress procedure, the brain was taken out and homogenized. Then the activities of SOD, GSH-Px and MDA level were measured. Results Compared to group N, both the activities of SOD in brain tissues of group E and group E+P were significantly decreased ( P <0.05 and P <0.01, respectively) while the MDA level increased ( P <0.05). However, the extent of changes in group E+P was more obvious than that in E. GSH-Px activities in E+P and E were significantly changed. However, the GSH-Px activity in E+P was decreased ( P <0.05) while the activity in E increased ( P <0.05).Conclusion The chronic emotional stress can reduce the antioxidative system by decreasing the antioxidative enzyme activity and potentiating the lipid peroxidation in the brain. It is also suggested that the combination of emotional stress and pregnancy can augment the oxidative damage in rats’ brain. Objective To observe the effects of chronic emotional stress on the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) and malonialdehyde (MDA) level in female rats’ brain. Methods The rats were randomly divided into 4 groups: normal control emotional stress group (group E), emotional stress + pregnancy group (group E + P) and regular drinking group (group R). Emotional stress in rats was induced by training rats with empty drinking bottles. Results the to group N, both the activities of SOD in brain tissues of group E and group E + P However, the extent of changes in group E + P was more obvious than that in E. GSH-Px activities in E (P <0.05 and P <0.01, respectively) + P and E were significantly changed. However, the GSH-Px Activity in E + P was decreased (P <0.05) while the activity in E increased (P <0.05) .Conclusion The chronic emotional stress can reduce the antioxidant system by decreasing the antioxidant enzyme activity and potentiating the lipid peroxidation in the brain. It is also suggested that the combination of emotional stress and pregnancy can augment the oxidative damage in rats’ brain.