To study on antioxidant effects in the liver of 40-week-old mouse, the sample were orally pretreated 5mg/kg/day for 5 days with red ginseng saponin components(total saponin, protopanaxadiol saponin, protopanaxatriol saponin, ginsenoside-Rd, ginsenoside-Re, compound-K) for 5 days. The ability of saponin to protect the mouse liver from oxidative damage was examined by determining the activity of superoxide dismutase(SOD), glutathione peroxidase(GPx) and the contents of glutathione, the level of malondialdehyde, The only protopanaxadiol among the ginseng saponin fractions was significantly increased the hepatic SOD activity(p<0.01). The red ginseng saponin induced a slight increase of GPx activity, especially ginsenoside Rd, compound K and protopanaxatriol treatments significantly increased its activity. The content of glutathione was significantly increased by total saponin, protopanaxadiol and ginsenoside Rd(p<0.01), but the oxidized glutathione level was lowered in all the red ginseng saponin. Finally, the level of malondialdehyde was significantly decreased by ginsenoside Rd and protopanaxadiol. In conclusion, protopanaxadiol and ginsenoside Rd among the saponin fraction were especially increased in the activity of hepatic antioxidative enzyme and decreased the lipid peroxidation that was expressed in term of MDA formation. This comprehensive antioxidant effects of red ginseng saponin seems to be by a certain action of saponin other than a direct antioxidant action.