Abstract: In the research,the polysaccharide from Cordyceps sinensis' mycelium culture had been extracted by alcohol sinking method.After been fractionated and purified with DEAE-52 cellulose column chromatography and Sephadex G-100 gel column chromatograph,two neutral polysaccharides were obtained which named EPS- 1w and EPS- 2w. UV- spectrophotometry,Sephadex G- 100 gel column chromatograph method and specific optical rotation method were used to identify the purity of these two polysaccharides. And the gel filtration method and physical and chemical experiments as well as high performance liquid chromatography had been used for analyzing the polysaccharides' relative molecular mass,physical and chemical characters and compositions. The results showed that both of EPS-1w and EPS-2w were homogeneous components,and they could be dissolved in the water,dilute acid and alkali.Their average relative molecular mass was about 4.65 × 104 u and 3.48 × 104 u.The EPS-1w and EPS- 2w were composed by D- mannose,D- glucose,D- galactose,and the amount of substance were 23.7∶ 6.2∶ 8.5 and 35: 3.6: 31.