The crude polysaccharide was extracted from cirsium japonicum DC.using hot water-ethanol method to remove lipid and precipitate proteins.Its contents was determined by phenol-sulphuric acid method after the sample was freeze-dried.The yield of the crude polysaccharide was 6.5%.The sample was further isolated into five subfractions(DJ1,DJ2,DJ3,DJ4 and DJ5)through ion-exchange chromatography of DEAE-cellulose.The highest yield is 8.06‰ from DJ2.