In this study, zinc oxide film is formed on magnesium alloy surface with RF power oxygen plasma, trying to improve corrosion resistance remained electric conductivity. By using plasma, the impact energies of zinc and oxygen ions on the magnesium alloy surface can be controlled by change of bias voltage supplied to the magnesium alloy. As a result, it is expected that the properties of the formed film can be changed. Authors selected zinc oxide because of its good electric conductivity. However, the effect on the corrosion resistance has not been clarified yet. The electric conductivity and the corrosion resistance of the coated zinc oxide film were investigated under the various experimental conditions.