Abstract: To study the antioxidative characteristics and activities of the ethanol and water extracts of Szechwan Lovage Rhizome(SLR) in several free radical models in vitro and in oxidative- damage model in mice. METHODS： The DPPH system model was applied to observe the inhibitory rates of DPPH radicals by different concentrations of SLR extracts. The chemiluminescence system models for determination of ·OH and O2-. were built to observe the inhibitory rates of luminous intensity by different concentrations of SLR extracts. The microsomal lipid peroxidation model stimulated by CHP, Vc /Fe2+ and CC14/NADP+ was established to observe the inhibition of MDA by different concentrations of SLR extracts. The oxidative-damage model in mice was built to observe the inhibitory rates of MDA and changes of liver protein CAT and SOD expressions. RESULTS: In the DPPH system, the inhibitory rates of DPPH radicals by the two SLR extracts were significantly higher than that in control group，with an evident dose-effect relationship. The IC50 of DPPH radicals by the ethanol and water extracts of SLR were 3.47 mg/ml and 6.09 mg/ml, respectively. In the two chemiluminescence systems, the inhibitory rates of ·OH and O2-. by different concentrations of SLR extracts were significantly higher than that in control group again with an evident dose-effect relationship. The IC50 of O2-. and ·OH by the ethanol extracts of SLR were 2.56 mg/ml and 4.21 mg/ml, respectively, and the IC50 were 2.34 mg/ml and 2.80 mg/ml, respectively, by the water extracts. Compared with that in control group, the content of MDA in the three LPO models was decreased significantly(P<0.05) at different concentrations and had a dose-effect relationship. In vivo studies, after SLR oral administration, decrease of MDA was observed in liver and serum. The expressions of SOD and CAT were increased by ethanol extracts. Water extracts only increased the expression of SOD but that of CAT was not altered. CONCLUSION：In several in vitro and in vivo models described above, the ethanol and water extracts of SLR exhibited effective antioxidative effects.

Key words: Szechwan Lovage Rhizome, DPPH, chemiluminescence, lipid peroxidation antioxidation