[目的]探讨不同剂量苯并[a]芘对小鼠肝脏的氧化损伤作用。[方法]用不同剂量(1mg/kg,2.5mg/kg,6.25mg/kg体重)苯并[a]芘对小鼠急性染毒,植物油为对照,2周后测定肝脏组织中超氧化物歧化酶(SOD)的活性、丙二醛(MDA)的含量,用单细胞凝胶电泳技术检测小鼠肝脏细胞DNA损伤情况。[结果]与对照组比较,各染毒组SOD活性均显著性下降(P﹤0.05),MDA含量显著升高(P﹤0.05),肝脏细胞彗星率随苯并[a]芘剂量增加而增加,彗星尾长随剂量增加而延长(P﹤0.01)。[结论]苯并[a]芘对小鼠肝脏有明显的氧化损伤作用。 [Objective] To investigate the oxidative damage of liver caused by different doses of benzo [a] pyrene in mice. [Method] Acute exposure to mice and vegetable oil were used as control in different doses (1mg / kg, 2.5mg / kg, 6.25mg / kg body weight) of benzo [a] pyrene. After 2 weeks, the superoxide dismutase (SOD) activity and malondialdehyde (MDA) content in the liver were detected by single cell gel electrophoresis. [Results] Compared with the control group, the activity of SOD in each group was significantly decreased (P <0.05) and the content of MDA was significantly increased (P <0.05). The comet rate of hepatic cells increased with the increase of the dose of benzo [a] pyrene , Tail length of comets extended with dose (P <0.01). [Conclusion] Benzo [a] pyrene has obvious oxidative damage on mouse liver.