Co-B amorphous alloy powders have been synthesized by chemical reduction of cobalt chloride with potassium borohydride in an aqueous solution. We find that this alloy can be used as an anode catalyst for a direct borohydride fuel cell (DBFC). This catalyst exhibits excellent electrocatalytic activity. An essential power output of 220mWcm−2 has been achieved at 15°C, and a life test last for 160h with no attenuation has been observed. The amorphous structure of the CoB alloy is still stable after the life test.