Abstract: Hydrogen storage alloys was successfully prepared by the spontaneous reaction synthesis process. The steps of the spontaneous synthesis process comprises: (a) premixing high H adsorption powder(A), low H adsorption powder(B), catalyst powder(C) with fuel element(D) in an amount corresponding to the atomic ratio of said hydrogen storage alloys, (b) pressing and forming the premixing powders to a predermined density; (c) placing the mixture of step (b) to a spontaneous sysnthesis reactor under protecting environment; (d) preheating the mixture at a temperature of about from 300.degree. to 600.degree. C.; and (e) partially igniting the mixture at a temperature higher than the melting point of the powders used in step (a) to propagate the spontaneous synthesis reaction.