In this study, the hydrogen desorption properties for the reactions between 1 mol% MNH2-added (M = Li, Na, and K) lithium hydride and NH3 (0.5 MPa, NH3/LiH = 1 mol/mol) at 100 degrees C were systematically investigated to design a LiH-NH3 hydrogen storage system with better kinetic properties. It is found that all of the alkali metal amide additives can improve the hydrogen desorption kinetics of the LiH-NH3 system, among which, LiNH2 shows the best effect. As compared to the other LiNH2-added composition, the 1 mol% LiNH2-added composition shows the best effect on improving the desorption kinetics of the LiH-NH3 system. According to the kinetic analysis, it is proposed that the effect of LiNH2 on the hydrogen desorption kinetics would be mainly due to physical effect.