The cultured mycelial cells of Ganoderma lucidum was extracted by alkali, and then neutralized by acid. The extract was passed through the column of DEAE cellulose for more purification. The neutral fraction was concentrated and precipitated with 95% ethanol. The precipitate was lyophilized and then PSG(polysaccharides) was obtained. PSG was composed of 82.2% polysaccharide, 0.7% protein and 17.1% uronic acid. Sugar conjugates of its hydrolysates were produced using with fluorescent compound(7-amino-1,3-naphthalene disulfonic aicd : 7-AGA), and then fluorescent labeled sugar conjugates were separated by reverse phase high perfomance liquid chromatography. Hydrolysates of PSG were composed of sixteen amino acids and 95.7% glucose, 2.7% xylose, 1.6% fucose and tract amount of galactose and mannose. The immunomodulating effects of PSG on macrophage were perfomed using murine macrophage cell line ATCC TIB 71 cells. PSG augumented the phagocytic activity of TIB 71 cells against fluorescent latex beads.