The inhibition performance and mechanism of molybdate in combination with Zn²⁺as inhibitors for magnesium alloy were studied in 3 . 5 % NaCl solution by using potentiodynamic polarization curves. The results show that the synergistic inhibition by 0 . 05 mol / L molybdate in combination with 0 . 005 mol / L Zn²⁺demonstrates strong inhibition to the corrosion of AZ31 magnesium alloy exposed to NaCl solution. The adsorption acting of MoO₄^2-is promoted on the alloy surface by Zn²⁺,what hold better resistance performance than that of single molybdate corrosion inhibitor. The mixture consisting of molybdate and Zn²⁺is an inhibitor through forming a compact protective layer that covered the magnesium alloy surface.