A neutral polysaccharide, GP, was isolated from a fermentation broth of Ganoderma lucidum Acid hydrolysis and a paper chromatography analysis indicated that the polysacchride was composed of glucose, xylose, and mannose. The molecular weight was estimated to be $2.9{ imes}10^4$. The oral administration of GP to mice showed that it can inhibit liver damage induced by GalN and $CCl_4$.