Electrochemical method was utilized to study the corrosion resistance of zinc alloy coatings. These coating, plated by mechanical plating, include pure zinc coating, Zn-Al coating, Zn-Mn (5:1) coating, Zn-Mn-Al (5:1:1) coating. The parameters in Stern-Geary formula were obtained by several tests. According to these parameters, corrosion electric current was calculated. The corrosion resistances of these zinc alloy coatings were compared by corrosion electric current. Results indicate that the corrosion resistance of Zn-Al coating was the best in these zinc alloy coatings. And the sequence of these coatings ranged from high corrosion resistance to low corrosion resistance was as follow, Zn –Al> Zn-Mn-Al (5:1:1)>Zn> Zn-Mn (5:1).