Abstract: Objective To investigate the antioxidant activities of taur ine on sarcoma 180(S₁₈₀)bearing mices.Methods Sixty Kunming mices were divided randomly into five groups.Groups A,B,C were drank with 0.5%,1.0%,1.5% taurine respectively;group D was cyclophosphamide positive control;group E was the tumornegative control.Then mices were vaccinated with 0.2 ml S₁₈₀ cell suspension in leftaxillas.24 hours later,the positive control was injected by cyclo phosphamide 20 mg/(kg·bw).After 1 week,the content of maleic dialdehyde(MDA)and the activity of superoxide dismutase(SOD)and glutathione peroxidase(GSH-Px)in plasma and liver were detected with test kit respectively.Erythrocytic haemolysis rate induced by H₂O₂ was studied.L ymphocyte were separated for determination of DNA damage by using SCGE.Results Compared with negative control,the activity of SOD and GSH-Px in plasma and liver of taurine groups increased(P<0.05 or P<0.01)and the content of MDA in plasma decreased(P<0.01)significantly.Erythrocytic haemolysis rate of 0.5% and 1.5% taurine groups were markedly lower than the negative control(P<0.05).There was a decr easing tendency of the oxidative DNA damage on peripheral lymphocytes induced by 5,10 and 25 μmol/L H₂O₂.The DNA damage was obviously lower than the negative control in 1.0% and 1.5% taurine groups induced by 10 mol/L H₂O₂ and in 1.5% taurine group in duced by 25 μmol/L H₂O₂(P<0.05 or P<0.01).Conclusion Taurine can improve antioxidative effect of S₁₈₀,bear ing mices,which may be associated with its effects of increasing antioxidase activity and reducing lipid peroxidation and protecting the membrane of erythrocytic and resisting oxidative DNA damage.