Magnetically recyclable Co-B hollow nanospindles have been prepared by using poly(styrene-co-methacrylic acid) nanospindles as scarified templates for the first time. The effect of the weight ratio of poly(styrene-co-methacrylic acid) to Co(OAc)(2) on the structure of Co-B hollow nanospindles is not significant. In the hydrolysis of ammonia borane to release H-2, the activity of Co-B hollow nanospindles was much higher than that of regular Co-B prepared without templates. Their catalytic performance is comparable to that of the reported Pt black concerning hydrogen yield. The favorable activity is attributed to the large specific surface area and hollow structure. In addition, Co-B hollow nanospindles have good reusability in the application due to their unique magnetic properties.