Abstract: Objective: To investigate the roles of cellular antioxidative systems in human hepato-cellular carcinoma, activities of antioxidative enzymes and to analyze related parameter between hepato-cellular carcinoma and normal liver tissues adjacent to the hepatocellular carcinoma. Methods: The activities of cytosolic catalase (CAT), superoxide dismutase, glutathione peroxidase (GSH- Px), glu-tathione S-transferase and the levels of reduced glutathione, total protein thiols and malondialdehyde were assayed. Results: Hepatoma tissues showed higher activities of CAT, GSH- Px and lower contentof total antioxidative capacity than that in adjacent normal paraneoplastic liver tissue (P<0.05). Con-clusion: These findings suggested that the antioxidative defense- related enzymes and antioxidant were largely regulated in hepatoma cells.