In this study, the influences of aluminum and tin additions (individual and combined) on corrosion behavior of magnesium alloy have been determined. The studied alloys were fabricated by permanent mold casting method to measure the corrosion properties, a potentiodynamic test, hydrogen evolution test and immersion test were carried out in a 3.5% NaCl solution at pH 7.2. From the results of microstructure analysis, the Mg-9Al-1Zn alloy was found to be composed of α-Mg and rod-like Mg17Al12 phase and the Mg-5Sn-5Al-1Zn alloy was found to be composed of α-Mg, rod-like Mg17Al12 and Mg2Sn phases. In the case of the Mg-9Sn-1Zn alloy, the microstructure was composed of α-Mg and eutectic Mg2Sn phase. With Sn addition (individual and combined), the corrosion resistance of the Mg alloys improved.