Mycelium of a cultivated strain of Poria cocos was grown by submerged fermentation in a liquid mediumcontaining corn steep liquor with orbital shaking. Six polysaccharides coded as ac-PCM1, ac-PCM2, ac-PCM3-Ⅰ andⅡ, ac-PCM4-Ⅰand Ⅱ were isolated from the myelium by extracting with 0.9% NaCl aqueous solution, hot water, 0.5 mol/L NaOHaqueous solution and 88% formic acid. Exo-polysaccharide was obtained from the culture medium and coded as ac-PCM0.The monosaccharide composition and molecular weights of these polysaccharides were characterized by using infraredspectroscopy, gas chromaography, elemental analysis, ~(13)C-NMR, viscometry and light scattering. The results indicated thatac-PCM0, ac-PCM1 and ac-PCM2 are heteropolysaccharides containing glucose, galactose, mannose and fucose, and ac-PCM3-Ⅰ and ac-PCM3-Ⅱ mainly consist of D-glucose. The content of the glucose in the polysaccharides increased with theisolation progress. Remarkably, α-glucan and β-glucan coexisted in the extract by NaOH aqueous solution (ac-PCM3), andcould be separated by chemical methods. The protein in the ac-PCM polysaccharides cultured from the medium containingcorn steep liquor was higher than that in the ab-PCM from the medium with bran extract. Therefore, the polysaccharidesfrom Poria cocos mycelia cultured in different media have different chemical composition, molecular weights and conformations. Mycelium of a cultivated strain of Poria cocos was grown by submerged fermentation in a liquid medium containing corn steep liquor with orbital shaking. Six polysaccharides coded as ac-PCM1, ac-PCM2, ac-PCM3-I and II, ac-PCM4- isolated from the myelium by extracting with 0.9% NaCl aqueous solution, hot water, 0.5 mol / L NaOH aqueous solution and 88% formic acid. Exo-polysaccharide was obtained from the culture medium and coded as ac-PCM0. monosaccharide composition and molecular weights of these polysaccharides were characterized by using infrared spectroscopy, gas chromaography, elemental analysis, ~ (13) C-NMR, viscometry and light scattering. The results indicated that ac- PCM0, ac- PCM1 and ac- PCM2 are heteropolysaccharides containing glucose, galactose, mannose and fucose, and ac-PCM3-I and ac-PCM3-II mainly consist of D-glucose. The content of the glucose in the polysaccharides increased with the isolation of progress. Remarkably, α-glucan and β- glucan coexisted in th e extract by NaOH aqueous solution (ac-PCM3), and can be separated by chemical methods. The protein in the ac-PCM polysaccharides cultured from the medium containing corn steep liquor was higher than that in the ab-PCM from the medium with bran extract. Therefore, the polysaccharidesfrom Poria cocos mycelia cultured in different media have different chemical composition, molecular weights and conformations.