A gel-forming (1->3)-b-D-glucan, grifolan (GRN) from edible mushroom, enhances various immunological activities. In this paper, effect of GRN on the induction of cytokines and nitric oxide by macrophage (MP) cell line (RAW264.7), peritoneal MP (PM) and kupffer cell would be shown. GRN bound to MP was detected immunohistochemically using anti-GRN antibody. GRN could induce production of TNF , IL-1 , and IL-6 by RAW264.7. MP also induced those cytokines by incubation with GRN. GRN induced phosphorylation of MAP kinase and p38 of PM.