A gas diffusion electrode is one of the most important components of a zinc-air battery. In this study, conducting polypyrrole coatings were prepared by electrochemical polymerization onto an SS304 current collector to improve the performance of the gas diffusion electrode. It was found that anodic polarization current of the SS304 current collector with the polypyrrole coating diminished in a 8 M KOH electrolyte solution. Furthermore, the oxygen reduction on the gas diffusion electrode was markedly promoted by the polypyrrole coating with certain catalysts, namely Ag and manganese oxide. The catalysts were deposited onto the polypyrrole coating on the SS304 current collector prior to the manufacturing processes of the gas diffusion electrode.