Objective: To study the antioxidative effect of ethanol extract of Rhaponticum uniflorum. Method : The effect of R.uniflorum ethanol extract on the total antioxidant capacity of liver was determined by ferric reducing method

and the anti-lipid peroxidative activity was detected by thiobarbituric acid (TBA) method. Result :R. uniflorum ethanol extract concentration-dependently elevated the total antioxidant capacity of liver homogenate

inhibited the lipid peroxidation of liver homogenate induced by H2O2

·OH and Fe2+ with the IC50s of 56.4

144.2 and 355.6 mg ·L-1

respectively

and inhibited the lipid peroxidation of liver mitochondria induced by H2O2 and Fe2+ with the IC50s of 781 and 36.3 mg ·L-1

respectively. Conclusion: The ethanol extract of R. uniflorum has an antioxidative effect in vitro.