OBJECTIVE：To investigate the effect of increasing efficacy and decreasing toxicity of Limax extract （LE）on cyclophosphamide（CTX）in the treatment of hepatocellular carcinoma. METHODS ：The mice were randomly divided into normal group，model group ，CTX group （0.02 g/kg），LE low-dose ，medium-dose and high-dose groups （LEL，LEM，LEH group ，0.6，1.2，2.4 g/kg），CTX+LE low-dose ，medium-dose and high-dose combination groups （CTX+LEL，CTX+LEM，CTX+ LEH group ，the same dose as single drug group ），with 10 huangrenbin518@163.com mice in each group. Except for normal group ，other groups were inoculated with hepatoma cells H 22 in the left ar mpit to establish tumor bearing models. After 24 h of inoculation ，normal group and model group were intragastrically given normal saline ， and administration groups were intragastrically given corresponding drugs ，once a day ，for 10 days. On the second day after the last administration ，the general conditions of mice in each group were observed ；the body mass ，thymus index （LI），spleen index （SI）were measured ；the tumor inhibition rate was detected. The effect （q）of combination therapy was evaluated by King ’s formula . The counts of WBC ，RBC and PLT ，serum contents of ALT ，ALT，Scr and BUN were detected in model group ，CTX group and combination groups ，and the contents of MDA，SOD and GSH ，the levels of VEGF ，TNF-α and IL-6 in the tumor tissue were detected by colorimetry and ELISA in above groups. The protein expression of oncogenes （p53，Bcl-2 and Bax ）were detected by immunohistochemical method in model group，CTX group and CTX+LEM group. RESULTS ：The mice in the model group were in poor spirit and had symptoms of excessive drinking and eating ；although the body weight ，TI and SI were not significantly abnormal compared with normal group （P＞0.05），WBC count and AST content were significantly increased ，ALT and BUN contents were significantly decreased （P＜ 0.05 or P＜0.01）. Compared with model group ，above symptoms of mice were all improved in administration groups. The tumor weight of administration groups ，TI and SI of CTX group and TI of combination groups were decreased significantly ，but tumor weight of LEL group and LEH group ，TI and SI of LE single groups and combination groups were significantly higher than CTX group；tumor weight of combination groups were significantly lower than CTX group （P＜0.05 or P＜0.01）. The tumor inhibition rates of administration groups were 29.58％-72.08％. The q values of CTX+LEL group ，CTX+LEM group and CTX+LEH group were 1.03，0.97 and 0.86，respectively. Compared with model group ，WBC count ，AST and BUN contents of CTX group ，MDA contents of combination groups ，VEGF，TNF-α and IL-6 levels of administration groups ，the protein expression of Bcl- 2 in CTX group and CTX+LEM group were decreased significantly ；the activities of SOD and GSH of administration groups ，the protein expression of p 53 in CTX+LEM group and Bax in CTX group ，CTX+LEM group were increased significantly （P＜0.05 or P＜ 0.01）；WBC counts and AST contents of administration groups ，ALT content of CTX+LEM group ，SOD activity of CTX+LEH group and GSH activity of CTX+LEM group were all significantly higher than those of CTX group ；MDA content of CTX+LEH group，VEGF and TNF-α levels of CTX+LEM group and CTX+LEH group，IL-6 levels of administration groups were all significantly lower than CTX group （P＜0.05 or P＜0.01）. CONCLUSIONS ：LE combined with CTX can increase the anti-tumor effect，and LE can reduce the toxicity of CTX induced immunosuppression and bone marrow suppression in mice ，with effect of increasing efficacy and decreasing toxicity. The effect may be related to antioxidant stress ，inhibition of angiogenesis and secretion of inflammatory factors ，and regulation of apoptosis protein expression.