To investigate the effects of gymnocladas saponin's antioxidant and DNA damage intervention capacity on rats with high cholesterol levels as well as the effects of gymnocladas saponin on serum cholesterol and relative serum biochemical indexes on targets,48 healthy rats were randomly divided into three groups:a control group,a low concentration gymnocladas saponin group and a high concentration gymnocladas saponin group.Rats of three groups respectively fed with 0,80,200 mg/kg gymnocladas saponin,who then have DNA damage and high cholesterol levels are induced by H2O2 (0,6,12,18 μmol/L) of different concentration.After 60 days,the collection of the blood sample obtained with the kits are used to test serum level and activity of malondialdehyde (MDA) and glutathione peroxidase (GSH-PX) as well as the damage of lymphocyte DNA by single cell gel electrophoresis (SCGE).As a result of the test,compared with the control group,the different content of MDA and the different activity of GSH in the low concentration gymnocladas saponin group and the high concentration gymnocladas saponin group have statistical significance.The low concentration of gymnocladas saponin group and the high concentration of gymnocladas saponin groups' serum total cholesterol (TC),triglyceride (TG),apolipoprotein B (apoB) are significantly reduced,especially in the high concentration of gymnocladas saponin group.At the same time,the bile acid excretion in two groups of rats increases.The diffenrence of Apolipoprotein A-Ⅰ (apoA-Ⅰ) and high density lipoprotein cholesterol (HDL-C) level effect has no statistical significance.This illustrates that gymnocladas saponin can effectively reduce the level of plasma cholesterol,and can have significant effect on the content of GSH and MDA in serum of healthy young rats and on the protection of DNA damage induced by H2O2.