Abstract: Polysaccharides were one of the main components of Hedysarum polybotrys Hand.- Mazz( HPS).In this paper,the antioxidant activity of polysaccharides from Hedysarum polybotrys Hand.- Mazz with microwave-assisted extraction,ultrasonic assisted extraction and hot water extraction methods was investigated. HSP- M,HSP- C and HSP- H after deproteinization and vacuum freeze- drying were characterized by FT- IR and measured by GPC.The result indicated that HSP- M,HSP- C and HSP- H had typical absorption peak of polysaccharides,weight average molar mass( MW) were 6.29 × 105,4.56 × 105,5.13 × 105 and polydispersion and gyroradius determined were 3.42,3.22,2.31. Anti- oxidant effect on scavenging DPPH radicals,OH radicals and superoxide radicals and reducing power on HSP- M,HSP- C and HSP- H were measured. The resualts showed that anti-oxidant effect of HSP- M was higher than HSP- C and HSP- H. To get practical methods for the research and manufacture of HPS,microwave- assisted extraction method should be chosen.