Objective To study the effect of Acanthopanax Senticosus (APS) on the immune function and the activity of glutathione peroxidase (GSH-PX) and superoxide dismutase (SOD) during 3-MeDAB hepatocarcinogenesis of rats. Methods 46 male SD rats were divided into three groups randomly: control group received the basal diet, 3-MeDAB group received 0.06% 3-MeDAB in the diet for 10 consecutive weeks, then changed to basal diet, APS group received 0.06% 3-MeDAB along with APS (4.5 g/kg diet) daily in food for 10 weeks, then changed to basal diet along with the same dose of APS till the end of experiment. Phagocytic function of leucocyte was detected by chemiluminescence and the activity of GSH-PX and SOD by method of DTNB and xanthine oxidase. Results Peak/103 PMN and integral (CL 60 min) of 3-MeDAB group were higher than that of control group (P<0.05) and APS group (p<0.01). Phagocytic index/109 WBC of 3-MeDAB group was higher than that of APS group (P<0.05). GSH-PX activity in blood of APS group was higher than that of 3-MeDAB group (P<0.05) and was similar to control group. SOD activity in serum of APS group was higher than both control group (p<0.01) and 3-MeDAB group (P<0.05). MDA content in serum of control was lower than both APS group and 3-MeDAB group. Conclusions The effect of APS against cancer and its immunoregulatory function are evidenced through improving the activity of GSH-PX and SOD and depressing the lipid peroxidation and resisting the compensable increase of phagocytic function of leucocyte duing the hepatocarcinogenesis of rats.