This report describes an inhibitory effect of Tongku-tang(TKT) on mast cell-mediated immediate-type allergic reactions. TKT is an Oriental herbal prescription, which has been successfully applied for the treatment of allergic disorders, mainly skin anaphylactic diseases in eastern medicine. TKT has concentration-dependently inhibited the ear swelling response induced by intradermal injection of non-specific mast cell degranulator compound 48/80 in mice. TKT also inhibited mast cell-dependent passive cutaneous anaphylaxis activated by dinitrophenyl (DNP)-IgE antibody in rats. I studied the effect of TKT on the histamine and β-hexosaminase release from the rat peritoneal mast cells by compound 48/80. TKT did not inhibit significantly the histamine and β-hexosaminase release from the rat peritoneal mast cells by compound 48/80. However, TKT inhibited both TNF-α and IL-1β secretion induced by phorbol 12-myristate 13-acetate and A23187 respectively. These results provide evidence that TKT may be beneficial in the treatment of immediate-type allergic reaction.