Abstract: Gd-Zr -Mg master alloy was prepared by co-electrodeposition method using mixed Gd₂O₃-MgO-ZrO₂ as raw materials and GdF₃-LiF-BaF₂ as molten salt system. Effects of electrolysis temperature, cathode current density and content of ZrO₂ in raw materials on the current efficiency and alloy content of Zr in prepared master alloy were investgated. The results show that the current efficiency increased initially with electrolysis temperature and cathode current density then decreased, whereas decreased with increasing content of ZrO₂ in raw materials. And the content of Zr in master alloy increased with increasing electrolysis temperature and content of ZrO₂ in raw materials, whereas increased initially with cathode current density and then decreased. And the current efficiency was 57 % and content of Zr in master alloy amounted to 10 %~11 % under the optical electrolysis technique.