Abstract: The cathodic electrophoretic coatings were synthesized by grafting acrylic monomers onto bisphenol A epoxy resins. The reactive conditions and recipe were optimized by means of orthogonal design, including monomers reaction time, diethanolamine dosage, amination time, amination and neutralization temperatures. The structures of epoxy resin and synthesized epoxy-acrylic resin were characterized by FT-IR. The optimal conditions and recipes were determined.