Ni(Ⅱ) was reduced to Ni atom irreversibly by a one-step reaction in acetamide-urea-NaBr melt at 353K. The electron-transfer coefficient, and the diffusion coefficient, D0 were determined to be 0.21 and 1.15×10-8 cm2.s-1 on Pt electrode. Although the Ce（Ⅲ）and the Mg（Ⅱ）cannot be reduced to Ce and Mg alone, they can be inductively codeposited with Ni（Ⅱ）to obtain an amorphous Ce-Mg-Ni alloy film by potentiostatic electrolysis. The content of Ce in the alloy increase with the increasing of the molar ratio of Ce（Ⅲ）/Ni（Ⅱ） and reaches to the maximum of 49.70 wt%. The content of Mg in the alloy increase with the increasing of the cathode potential and the maximum was 4.558wt%.