Objectives: Rubi Fructus(fruit of Rubus coreanus Miq.) composed of Polygonum multiflorum THUNB. and some medical herbs is known as formula of senescence delay effect. The purpose of this study is to investigate the effect of Rubi Fructus(fruit of Rubus coreanus Miq.) on antioxidant enzyme activity such as Thiobarbituric acid reactive substance(TBARS), Superoxide dismutase(SOD), Catalase(CAT), Glutathione peroxidase(GSH-px) in rat erythrocytes and blood plasma. Methods: Sprague-Dawley rats were divided into 3 groups, Normal group(supplied enough water and feeds only, Normal Group), D-galatose administered group(injected D-galatose 50mg/kg, 1time/day for 6 weeks, Control Group) and Rubi Fructus (fruit of Rubus coreanus Miq.) administered group(D-galactose 50mg/kg and Rubi Fructus(fruit of Rubus coreanus Miq.) extracts 85.0mg/200g 1time/day for 6 weeks, BBJ Group). Rats were sacrificed and TBARS, SOD, CAT, GSH-px, Plasma total lipid, Plasma triglyceride and cholesterol were measured in rat erythrocytes and blood plasma. Results : Plasma TBARS concentrations of all experimental group were not significantly different. Red blood cell(RBC) SOD activities of BBJ group was increased, and RBC catalase activities of all experimental group were not significantly different. RBC GSH-px activities of BBJ group was increased. Plasma total lipid concentration of BBJ group were significantly lower than those of control. Plasma triglyceride, total cholesterol and HDL-cholesterol concentrations of all experimental group were not signi ficantly different. Conclusions: According to the above results, it is considered that Rubi Fructus(fruit of Rubus coreanus Miq.) is effective in inhibiting lipid peroxidation and increasing antioxidative enzyme activities in D-galactose induced aging rat.