Objectives: Younnyeniksoobulrodan(延年益壽不老丹) 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 Younnyeniksoobulrodan(延年益壽不老丹) on antioxidant enzyme activity such as Thiobarbituric acid reactive substance(TBARS), Superoxide dismutase(SOD), Catalase(CAT), Glutathione peroxidase (GSH-px) in rat erythrocytes and liver. Methods: Sprague-Dawley rats divided into 4 gorups, Young group(8 weeks old, N-8), Aging group(18 weeks old, N-18), pathologically induced aging gorup(injected D-galatose 50mg／kg, 1time／day for 6 weeks, CON) and Younnyeniksoobulrodan(延年益壽不老丹) administered group(D-galactose 50mg／kg and Younnyeniksoobulrodan extracts 840.0mg／kg 1time／day for 6 weeks, YIB). Rats were sacrificed and TBARS, SOD, CAT, and GSH-px were measured in rat erythrocytes and liver. Results: Plasma and liver TBARS concentrations of YIB group were significantly lower than those of control. Red blood cell(RBC) SOD activities of YIB group was increased(F=3.445, p=0.033, ANOVA test), and RBC catalase activities of all experimental group were not significantly different. RBC GSH-px activities of YIB group was increased(F=9.365,p=0.0001, ANOVA test). Liver SOD activities of YIB group was higher than those of control(F=4.967, p=0.008, ANOVA test). Liver catalase activities of all experimental group were not significantly different, and liver GSH-px activity of YIB group was significantly higher than that of control(F=3.846, p=0.022,ANOVA test). Conclusions: According to the above results, it is considered that Younnyeniksoobulrodan is effective in inhibiting lipid peroxidation and increasing antioxidative enzyme activities in D-galactose induced aging rat.