Ni-Cu-P coating was synthesized on copper substrate by electroless plating technique.The coating morphology and com-position were characterized by SEM and EDX.The corrosion resistance of Ni-Cu-P coating was studied by PC and EIS.The results show that at a higher electrolyte concentration,Cl-and SO42-ions promote the dissolution rate of Ni by their adsorption,and accelerate the passivation of Ni-Cu-P coating,at lower electrolyte concentration,Ni-Cu-P coating is not easy to passivate as the reducing of the ad...