CeCo 5 alloy was prepared from the mixture of cobalt oxide (Co 3 O 4 ) and cerium oxide (CeO 2 ) powders by electro-deoxidation in molten calcium chloride. The effects of the cell voltage and sintering temperature on the electrolysis process were reported. The electro-deoxidation mechanism was investigated by potentiodynamic polarization using a molybdenum cavity electrode in conjunction with characterization of the products from constant voltage electrolysis under different conditions by XRD and SEM. The electrochemical property of CeCo 5 alloy was investigated by cyclic voltammetry measurements. The results show that the electro-deoxidation rate increases with increasing the cell voltage and decreasing the sintering temperature. The pure CeCo 5 can be prepared by direct electro-deoxidation of mixed CeO 2 /Co 3 O 4 pellets sintered at 850 °C when the cell voltage of 3.1 V is applied. The electro-deoxidation proceeds by the simultaneous reduction of Co 3 O 4 to Co and reduction of CeO 2 to CeOCl, followed by CeOCl reduction on the pre-formed Co to form CeCo 5 alloy which shows a good cycling stability.