To investigate the deaging effects of introperitoneally injected Chondroitin Sulfate (CS) on various enzyme activity (AST, ALT, MDA (Malon dialdehyde), SOD (Superoxide dismutase), GPx (Glutathione peroxidases) and histophathology of liver tissue, ovariectomized rats were used. The antioxidative effects of chondroitin sulfate (100 mg/kg and 200 mg/kg body weight) were investigated at the antioxidative enzyme activities of liver homogenate fractions (liver total homogenate, mitochondrial, and microsomal fractions) and sera. In addition, the rat liver was histologically examined. Intraperitoneally injected CS, depend on dosage, indicated a protective effect against ovariectomy-inducted aging. Moreover, inflammation and cirrhosis in liver tissue of CS treated group were significantly decreased. Based on these results, intraperitoneally injected CS is a useful material to delay aging.