Refined polysaccharides were obtained by water extraction,then alcohol precipitation,Sevag protein removal method and macroreticular resin decolorization.Then the refined polysaccharides was tested on mice.The effects on the weight of mice,visceral index,total cholesterol(TC),triglyceride(TG),low-density lipoprotein cholesterol(LDL-C),high density lipoprotein cholesterol(HDL-C) and atherosclerosis index(AI) of mice serum were studied.Results indicated that in the high-dose polysaccharide group,the weight of mice and visceral index were dropped dramatically on group,do did TC,TG and LDL-C of mice serum and AI;HDL-C was significant increased.In the medial-dose group,TG and LDL-C of mice serum and AI were dropped dramatically.In low-dose group,TG of mice serum and AI were able to drop dramatically.These results demonstrated that ginkgo nut fine polysaccharide could reduce plasma lipids and had a certain effect in preventing coronary heart disease and atherosclerosis.