Abstract: In this spaper, corrosion resistance of Zn-Al-Mg-Ce alloy in water of Yangtse River and 3.5% NaCl aqueous solution was studied in comparison with Zn, Zn-Al, and Zn-Al-Mg alloys or metal.On the basis of experimental results of microstructure and composition of samples by means of SEM and EDX respectively and Fermi level theory, the mechanism of corrosion resistance was derived.The results showed Zn-Al-Mg-Ce alloy exhibited minimum electrode potential, corrosion current and corrosion rate among the tested alloys or metal, regardless of in water of Yangtse River and 3.5% NaCl aqueous solution.The order of corrosion rate of tested alloys or metal is Zn-Al-Mg-Ce < Zn-Al-Mg < Zn-Al < Zn, and the corrosion rates of Zn-Al-Mg-Ce alloy in water of Yangtse River and 3.5% NaCl aqueous solution are 19.4% and 23.7% of that of Zn metal, respectively.The excellent corrosion resistance can be attributed to Ce which decreased the potential difference between the grain interior and grain boundary and restrained the intergranular corrosion.