Gunjung-tang(GJT) has been reported at Shanghanlun(傷寒論), which has been used for the treatment of general weakness, digestive organ disease and the treatment of allergic disorders in clinical medicine. However, its effect in experimental models remains unknown. In a rat and mouse model, the role of GJT was examined in mast cell-dependent allergic reactions and secretion of inflammatory cytokines. GJT inhibited anti-dinitrophenyl IgE antibody-induced passive cutaneous anaphylaxis reaction by Intraperitoneal pretreatment. GJT inhibited both IL-1β and TNF-α secretion on egg albumin induced allergic tissues and compound 48/80 induced thymus. Furthermore, GJT enhanced Band T lymphocytes proliferation. Our findings provide evidence that GJT inhibits the IgE-dependent allergic reactions and inflammatory cytokines secretion, and enhanced immune response.