The electrochemical behaviors of AZ magnesium alloys in 1.0 mol/L Mg(ClO4)2 solution were investigated by mass loss, linear sweep voltammetry (LSV), electrochemical impedance spectroscopy and chronopotentiometry, in order to examine their performances as negative electrode material in magnesium battery. The results of immersion and LSV show that the self-corrosion rate of AZ21 is larger than that of AZ31 and AZ61; AZ21 and AZ31 are more active than AZ61, exhibiting less anode polarization and negative open circuit potential. The EIS show Rct of AZ21, AZ31 and AZ61 magnesium alloys gradually increase. In the discharging experiment, the discharge potential of AZ31 is negative and stable. The anodic current efficiency of AZ31 is 82%, higher than that of AZ21 and AZ61 magnesium alloys. The delay time of AZ31 is 2 s, shorter than that of the AZ21 and AZ61. Thus, the AZ31 magnesium alloy is more excellent as anodic material of Mg battery.