The effect of Ce and Ni contents on the glass-forming ability (GFA) of Mg-Ce-Ni system in the Mg-rich corner of Mg-Ce-Ni system is revealed. Ce is more advantageous for the GFA of Mg-rich Mg-Ce-Ni system than Ni, and the lowest Ce content is similar to 5 at.% to obtain the fully amorphous alloy. Amorphous alloy with the highest Mg content, Mg90Ce5Ni5, was obtained by melt-spinning. With the amorphous alloy as precursor, nanostructure multi-phases compositae was prepared by crystallizing it in hydrogenation process. The compositae with reversible hydrogen storage capacity of 5.3 wt.% shows much faster kinetics and lower MgH2 desorption activation energy than those of induction-melt Mg90Ce5Ni5 alloy. Both in situ formed nanosized Mg2Ni and CeH2.73 act as effective catalysts and significantly improve the hydrogen storage properties of MgH2. Copyright (C) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.