Magnesium base alloys with aluminum and zinc were obtained through electrochemical co-deposition from LiCl-NaCl-MgCl2 melt. The possibility of electrochemical co-deposition was discussed in detail by electro-analytical methods. The co-deposition happens when the concentration of aluminum and zinc ions were kept at low value and the current density is high enough. The components of alloy elements can be controlled by fixing the components of the feeding salts with the expected component and consistent with the current. A laboratory test of the co-deposition was also performed and certain compositions of the Mg-Al, and Mg-Zn were obtained. The alloys obtained from the co-deposition show a typical microstructure.