For application to the treatment of wheat-sensitive allergy, we developed a practical method for producing a haptenic peptide mixture, and evaluated its haptenic properties. Wheat flour was hydrolyzed with chymotrypsin to obtain a hydrolysate, and the diffusible fraction from the hydrolysate was subjected to gel-filtration. The resulting oligopeptide fraction could bind to wheat-specific IgE antibodies in the serum of patients allergic to wheat. Since this peptide mixture did not induce histamine release from basophils in these patients, it was concluded that the peptide mixture was composed of monovalent haptens. Histamine release from antigenstimulated basophils was almost completely inhibited when the basophils were preincubated with the haptenic peptide mixture. These results suggest that this haptenic peptide mixture can regulate the allergenic reaction in an epitope-specific manner.