The hydrogen storage properties of the nanocomposite Mg 95 Ni 3(MnO 2) 2 (mass fraction, %) were studied. The temperature changes in hydriding/dehydriding process were investigated. The nanocomposite was fabricated by ball milling process of mixed elemental Mg, Ni and oxide maganese MnO 2 under hydrogen pressure (approximately 0.6?MPa). The hydrogen absorption and desorption properties of the samples milled for various times were investigated. A remarkable enhancement of hydrogen absorption kinetics and low operational desorption temperature have been found after the sample milled for over 57?h. For example, this nanocomposite can absorb hydrogen more than 6.0% (mass fraction) in 60?s at 200?℃ under 2.0?MPa, and desorption capacity also exceeds 6.0% (mass fraction) in 400?s at 310?℃ under 0.1?MPa. The storage properties of samples milled for various times were studied and the kinetics of the samples were analyzed. The hydrogen storage properties of the nanocomposite Mg 95 Ni 3 (MnO 2) 2 (mass fraction,%) were studied. The temperature changes in hydriding / dehydriding process were investigated. The nanocomposite was fabricated by ball milling process of mixed elemental Mg, Ni A remarkable enhancement of hydrogen absorption kinetics and low operational desorption temperature have been found after the sample milled For over 57? h. For example, this nanocomposite can absorb hydrogen more than 6.0% (mass fraction) in 60? s at 200? C under 2.0? MPa, and desorption capacity also exceeds 6.0% (mass fraction) in 400? s at 310 ° C under 0.1 MPa. The storage properties of samples milled for various times were studied and the kinetics of the samples were analyzed.