A nanoporous Ni layer on the surface of Mg was prepared utilizing the reduction reaction of Ni(2+) by Mg in NiCl(2)center dot 12H(2)O solution. XRD result showed that the product was composed of cubic Ni, hexagonal Mg and little Mg(OH)(2). SEM and TEM results suggested that a nanoporous Ni layer microencapsulated Mg and formed Ni@Mg. The specific surface area of Ni@Mg formed in this reaction was 65.3 m(2)/g. Hydrogen uptake increased as the temperature increased. Moreover, Ni@Mg showed a reversible hydriding-dehydriding process without formation of the stable hydrides, which indicated that the nanoporous Ni layer on the surface of Mg showed an obvious physisorption characteristics rather than hydrogen storage behavior of Mg. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.