To improve the current efficient of Al-Zn-Sn alloy, the influence of different contents Ce on the microstructures and electrochemical properties of alloy was investigated. The results show that the appropriate amount of Ce was effective on improving the electrochemical properties of Al-Zn-Sn alloy. The corrosion potential shifted negatively and the current efficiency increased with the increasing of Ce contents. The optimal microstructure and electrochemical properties were obtained when the Ce content in the alloy was 0.5 wt.%. The good electrochemical properties of Al-7Zn-0.1Sn- 0.5Ce (wt.%) alloy is mainly attributed to the fine grains and the less segregation phases at grain boundary.