A trifunctional epoxy resin, N-phenyl-p-phenylenediamine triglycidylamine (ADPTGA), was synthesized by a two-step process using N-phenyl-p-phenylenediamine (ADPA) and epichlorohydrin (ECH) as raw materials, and benzyltriethylammonium chloride (TEBAC) as a catalyst.The structural composition of ADPTGA was characterized by FTIR and 1HNMR. ADPTGA was added to bisphenol A epoxy resin (E-51) and cured with diaminodiphenylmethane (DDM) as the curing agent to investigate the effect of ADPTGA addition (calculated by E-51 quality, hereinafter) on the performance of the composite epoxy resin system based on the viscosity determination, storage stability test, mechanical property test, TGA, SEM and other tests. The curing kinetics of E-51/DDM (phr) and ADPTGA/E-51/DDM systems were analyzed by non-isothermal DSC tests. The results showed that the epoxy value of ADPTGA was 0.68 mol/100 g, and the viscosity was 5~6 Pa·s at 25 ℃. When the ADPTGA was added at 10%, the cured product (10 phr) of ADPTGA/E-51/DDM system had the best performance, and its tensile strength, elongation at break, flexural strength, and impact strength were increased by 45.8%, 54.5%，22.8% and 41.2%, respectively, compared with that of phr , and the glass transition temperature (Tg) increased by 5.5 ℃; the results of the curing process of phr and 10 phr were in accordance with the two-parameter autocatalytic (?esták-Berggren) model, and the curing process was unaffected by the rate of temperature increase (5~20 ℃/min).