Abstract: AIM :To study the protective effect of hepatic stimulator substance (HSS)on chemotherapeutic liver damage induced by cyclophosphamide and its possi- ble mechanism.METHODS:The serum biochemical pa- rameters, oxidative parameters and anti-oxidative parame- ters of liver tissue of male Kunming mice inoculated with S₁₈₀ cells were measured .The pathology of the liver was observed with microscope .The weight of S180 sarcom was weighted .RESULTS:The elevation of MDA content of liver tissue and the less of GSH content and CAT , GSH- PX , GST , and SOD activities induced by CP were re- stored remarkably by HSS .The ALT and LDH activities of serum in HSS group which was compared with control group and CP group were not statistically distinctive .In the pathologic examination , spotty and focal necroses of hepatocytes in the liver of CP group were found with a great deal of inflammatory cells infiltration in the necrotic and portal areas, while the damage in the liver of HSS group was ameliorated obviously ;The weight of S₁₈₀ sar- com in CP group and HSS group was not statistically dis- tinctive .CONCLUSION:The effect of HSS on CP-in- duced chemotherapeutic liver damage maybe due to anti- oxidative activity .

Key words: cyclophosphamide , chemotherapeutic liver damage , hepatic stimulator substance , oxidative stress , protect liver