Ammonia borane (NH₃BH₃) is able to hydrolyze at room temperature to generate hydrogen with high purity. For this feature, ammonia borane is expected as a hydrogen storage material for polymer membrane fuel cells for mobile use. It is reported that metal-based catalysts show high active for this reaction. Their catalytic activity was influenced by the morphology of their active species. In order to investigate the influence of the morphology, we have focused on spherical particle materials with hollow void because of their easily controllable homogeneity. In our researches, we have found that hollow nickel-silica composite spheres were fabricated from the spherical composite particles by in-situ activation of the particles with small amount of sodium borohydride during hydrolysis of ammonia borane, and the hollow spheres show high activity for the hydrogen generation from aqueous ammonia borane solution. In this study, we fabricated the highly active in-situ synthesized hollow ruthenium-silica composite spheres using the same method and investigate the effects of the preparation conditions on their catalytic activity for hydrolytic dehydrogenation of ammonia borane.