For the economic manufacturing of Mg₂Ni hydrogen absorbing materials, Mg and Ni chips were mechanically alloyed under 20 bar`s hydrogen atmosphere. The homogeneous Mg₂NiH_x was formed after 48hr M.A (Mechanical Alloying). The hydrogen content of Mg₂NiH_x reaches 1.75wt.% and the dehydriding reaction starts at around 210℃ The specific magnetization value is reduced from 13.7 emu/g to 0.13 emu/g with respect to mechanical alloying time. The homogeneous Mg₂NiH_x composites were obtained after 96 hr M.A. They are composed of the crystalline matrix phase and the disordered interface phase which seems to be the reason of the elevated dehydriding kinetics and decreased magnetic intensity.