Mg and Mg alloys are attractive hydrogen storage materials because of their lightweight and high absorption capacity. Their range of applications could be further extended if their hydrogenation properties and degradation behavior could be improved. The main emphasis of this study was to find an economic manufacturing method for Mg–Ti–Ni–H systems, and to investigate their hydrogenation properties. (Mg 10− x Ti x )–10, 20 mass% Ni systems were prepared by hydrogen-induced mechanical alloying (HIMA) using Mg and Ni chips and sponge Ti. The particles synthesized were characterized by X-ray diffraction, and their morphologies were observed by means of scanning electron microscopy (SEM) with energy dispersive spectrometry (EDS). The absorbed hydrogen capacity (AHC) was measured by using thermogravimetry analysis (TGA) after HIMA. In addition, the crystal structures were analyzed in terms of their bright-/dark field images and the selected area diffraction pattern (SADP) of transmission electron microscopy (TEM). In order to examine hydrogenation behavior, a Sieverts type automatic pressure–composition–isotherm (PCI) apparatus was used and the experiments were performed at 423, 473, 523, 573, 623 and 673 K. The results of TGA reveal that the absorbed hydrogen contents are around 2.5 mass% for (Mg 9Ti 1)–10 mass% Ni. With increased Ni content, the absorbed hydrogen content decreases to 1.7 mass%, whereas the dehydriding starting temperatures are lowered by some 70–100 K. The results of PCI on (Mg 9Ti 1)–20 mass% Ni show that its hydrogen capacity is around 5.3 mass% and its reversible capacity and plateau pressure are also excellent at 523 and 573 K. In addition, the reaction enthalpy, Δ H D.plateau, is −30.6±5.7 kJ/mol H 2.