In this study, we investigated the effect of Phellinus baumii (PB) on immediate-type allergic reaction and inflammatory cytokine secretion. PB inhibited compound 48/80-induced systemic reactions in mice. PB inhibited compound 48/80-induced plasma histamine release. In addition, PB also inhibited the immunoglobulin (Ig) E-mediated local allergic reaction. Furthermore, PB decreased the phorbol 12-myristate 13-acetate plus calcium ionophore A23187-stimulated tumor necrosis $factor-alpha$ and interleukin-6 secretion in human mast cells. These results indicate that PB may be beneficial in the treatment of immediate-type allergic reactions.