Abstract: The result of isolation,purification and properties of polysaccharide from Osmunda japonica Thunb isreported .The crude polysaccharide from the rhizome of Osmunda japonica Thunb.(CPOJ)was obtained,0.2%CPOJwas fractionated by ion-exchange chromatography on DEAE-Sepharose F.F.(15.6% rate),and further purified by geltitration on Sephacryl S-400HR(50% rate).As judged by HPLC and SDS-PAGE electrophoresis,this polysaccharidewas homogeneous and the mean Mr estimated to be 7.41×105.The total sugar content was 95.8% by the method ofH2SO4-phenol.The IRspectra showed that it contained furanoside.

Key words: Osmunda japonica Thunb Polysaccharide purification properties