The composites of M(BH4) n-LiNH2 (1/2 n molar ratio, n = 1 or 2, M = Ca, Mg, Li) were synthesized by liquid ball milling. Samples were characterized by X-ray diffraction, thermogravimetry-differential thermal analysis-mass spectroscopy (TG-DTA-MS), and kinetic models (Achar differential/Coats-Redfern integral method). The higher-electronegativity metal M in M(BH4) n-4LiNH2 (M = Ca, Mg) samples not only enables [BH4]- group to release easily, so as to facilitate the interaction of [BH4]- and [NH2]- groups, but also restrains the NH3 release and slightly decreases the onset dehydrogenation temperature concluded by TG-MS. Moreover, in stage 1 (200-350 °C), the kinetics performances of M(BH4) n-4LiNH2 (M = Ca, Mg) samples are distinctly improved, that is, the activation energies of them are reduced by ca. 30% compared to those of sample LiBH4-2LiNH2. The outstanding contribution of the replacement of M(BH4) n with high-electronegativity metal ion is to both improve the kinetics performance by changing the kinetics mechanism and decrease the temperature range of the initial dehydrogenation region.