Abstract: According to the factors causing the corrosion of wires in printed circuit boards(PCB),electricity simulation test and EIS (electrochemical impedance spectroscopy) were applied to study the corrosion behavior of wires,and the corrosion resistance of the wires in three PCBs with different organic coatings were compared.The results show that though corrosion resistance of the wires in three kinds of PCBs have diffferences,their corrosion behavior were basically the same.With the extension of electricity,high-tension wires appeare rusty spots and the coatings of low-tension wires blister and the color darkens.At the initial corrosion state of the high-tension wires,resistance values of PCBs decrease.