Different-rate rapid quenching was used in the preparation of low-Co AB5 hydrogen storage alloys in order to improve its electrochemical properties. The results show that proper quenching not only increased discharge capacity greatly but also can improved cycle stability and discharge voltage property. Adopting 18 m/s rapid quenching, the alloy can get better electrochemical properties. Mierostructure and phase structure of as-cast and quenched alloys were observed by XRD and SEM. The rapid quenching effects on the electrochemical properties of low-Co hydrogen storage alloy are discussed.