Ganoderma applanatum is cultured in different mediums.The results show that synthetic medium has the highest sugar yield.The production of Ganoderma applanatum extracellular polysaccharide is 61.75 mg/100 mL and the intracellular polysaccharide is 0.51 mg/100 mL.The amount of activated carbon for decolorization is 1.5 g/50 mL in purifying ganoderma applanatum crude polysaccharide.The ratio of deproteinization processing is sample∶ chloroform∶ butanol=25∶ 5∶ 1;Ethanol of 1.5 volume was used to precipitate the polysaccharide.Ganoderma applanatum crude polysaccharide purification was optimized.After purification,the polysaccharide content in crude polysaccharide is increased from 21.6% to 33.6%,while the polysaccharide is lost 52.7%.