PURPOSE: A malleable magnesium alloy having exceellent plating adhesiveness, prepared by adding a fixed amount of Ca to an alloy based on the compositions specified by ASTM-AZ 61A and -AZ 80A.

CONSTITUTION: The magnesium alloy consists primarily of 5.8 to 9.2 wt% Al, more than 0.15 wt% Mn, 0.2 to 1.5 wt% Zn, less than 0.7 wt% C, less than 1.9 wt% impurities, and the remaing Mg.

EFFECT: Even if the Mg alloy is plated with 10μ thick Cu, plated with 15μ thick nonelectrolytic Ni, heated at 200°C for 2 hours, and then dipped in water for hardening, no abnormal phenomena and also no exfoliation take place in plated film.