Abstract: Diamine-based polybenzoxazine (Poly(Ph-mda)) coatings were prepared on mild steel (MS) through a simple dip coating and thermal curing method using diamine-based benzoxazine as precursor.Poly(Ph-mda) showed good film-forming property and adhesive ability on MS surface.The effect of curing temperature on anticorrosion property of polybenzoxazine films was investigated by Tafel curves and electrochemical impedance spectroscopy (EIS) measurements.The results revealed that Poly(Ph-mda) coated MS samples exhibited high anticorrosion performance.When the curing temperature was 150℃,samples showed the best anticorrosion properties with the corrosion current of 1.49×10^-8A/cm²,which decreased two orders of magnitude compared with that of bare MS (6.91×10^-6 A/cm²).