Objective : The objective of this study was to investigate the antioxidant effects of Mori Folium extract. Methods Total antioxidant status was examined by total antioxidant capacity(TAC) and total antioxidant response(TAR) against potent free radical reactions. The effect of Mori Folium extract was examined by measuring total phenolic content, concentration at which 1,1-dipheny1-2-picrylhydrazyl(DPPH) radical scavenging activity was inhibited, inhibitory effect on lipid peroxidation, and the effect on reactive oxygen species(ROS) generation. Results : 1. TAC and TAR of Mori Folium extract at the concentration of 5 mg/ml were 1.61 and 1.24 mM Trolox equivalents, respectively. 2. Total phenolic content of Mori Folium extract at the concentration of 5 mg/Ml was 1.70 mM gallic acid equivalent. 3. Concentration of Mori Folium extract at which DPPH radical scavenging activity was inhibited by 50% was 2.29 m9/m4 as compared to 100% by Pyrogallol solution as a reference. 4. The inhibitory effect of the extract on lipid peroxidation was examined using rat liver mitochondria induced by FeSO$_4$/ascorbic acid. Mori Folium extract at the concentration of 10 mg/ml significantly decreased thiobarbituric acid reactive substances(TBARS) concentration. The extract prevented lipid peroxidation in a dose-dependent 5. The effect of Mori Folium extract on reactive oxygen species(ROS) generation was examined using a celt-free system induced by hydrogen peroxide FeSO$_4$. Addition of 1 mg/ml of Mori Folium extract significantly reduced dichlorofluorescein(DCf) fluorescence. The extract caused concentration-dependent attenuation of the increase in DCF fluorescence, indicating that the extract significantly prevented ROS generation in vitro. Conclusion ; The antioxidant effects of Mori Folium extract seem to be due, at least in part, to the prevention offree radical-induced oxidation, fllowed by inhibition of lipid peroxidation.