[en] Two effective methods, 1) substitution of M elements and 2) preparation of appropriate mixtures, for decreasing the de-hydriding temperatures of M-N-H and M-B-H (M=Li, Mg) systems were briefly reviewed. The de-hydriding reactions of LiNH₂ and LiBH₄ with/without Mg substitutions proved that the de-hydriding temperatures become lower with the increasing Mg concentrations. Also, a mixture of Mg(NH₂)₂ and LiH, which was chosen as one of the best compositions with low de-hydriding temperature among mixtures of M(NH₂)_x and MH_y. Increasing the LiH ratio in the mixtures is one of the important techniques to prevent ammonia release. Moreover, the de-hydriding temperature of LiBH₄ was reduced by 150 K by mixing 2 M of LiNH₂, suggests that the stabilities of the de-hydriding reactions of complex hydrides can be controlled by introducing new pathways by mixing. (authors)