Abstract:BN3B, the polysaccharide component of the fruit of Ganoderma lucidum, has been shown to have immune activity. From BN3B four homogeneous polysaccharides were separated and purified. Chemical studies on the main components BN3B1 and BN3B3 indicated that BM3B1 contained only glucose and should he a gtuean containing β-(1→6)and (1→3)glycoside bonds and that BN3B3 was an arabinogalactan containing β-(1→6)and(1→3)glyeoside bonds.