The curing reaction and reaction mechanism of epoxy resin E-44, for which aromatic amine modified dicyandiamide was used as a curing reagent, were investigated by means of differen-tial scanning calorimetry (DSC). The results showed that the modified dicyandiamide had better curing characteristic than un-modified dicyandiamide for epoxy resin E-44, and the curing reac-tion could be carried out at moderate temperature. Apparent acti-vation energy of the curing reaction was decreased appreciably from 123.829 kJ/mol to 61.550-64.405 kJ/mol, and reaction order was decreased from 0.941 to 0.896-0.900. Curing reaction mecha-nism also was discussed. The curing reaction and reaction mechanism of epoxy resin E-44, for which aromatic amine modified dicyandiamide was used as a curing reagent, were investigated by means of differen-tial scanning calorimetry (DSC). The results showed that the modified dicyandiamide had better curing Apparent acti-vation energy of the curing reaction was rendered appreciably from 123.829 kJ / mol to 61.550-64.405 kJ / mol. mol, and reaction order was decreased from 0.941 to 0.896-0.900. Curing reaction mecha-nism also was discussed.