Electroreduction of Co(Ⅱ) to Co in acetamide urea NaBr melt at 353 K is irreversible in one step. α and D are determined as 0.23 and 2.24×10 -7 cm 2·s -1 . Y(Ⅲ) is not reduced to Y alone, but can be inductively codeposited with Co(Ⅱ). The amorphous Y Co alloy film was obtained by potentiostatic electrolysis. The content of yttrium in the yettrium cobalt deposits changes with the cathode potential, molar ratio of Y(Ⅲ)/Co(Ⅱ) and the electrolysis time, and can reach 83.93%. Α and D are determined as 0.23 and 2.24 × 10 -7 cm 2 · s -1. Y (III) is not reduced to The content of y alloy film was obtained by potentiostatic electrolysis. The content of yttrium in the yettrium cobalt deposits changes with the cathode potential, molar ratio of Y (lll) / Co (Ⅱ) and the electrolysis time, and can reach 83.93%.