Abstract: The effects of sintering temperature and rare element Nd on the phase structures,morphology,pressure-composition-temperature(PCT) curves and hydrogen absorption/desorption kinetics characteristics of Mg_2-xNd_xNi(x=0,0.1,0.2,0.3)alloys prepared by spark plasma sintering(SPS) were investigated by X-ray diffraction(XRD),scanning electron microscopy(SEM) and PCT experiments.The structures and hydrogen storage properties of the Mg-based alloys prepared by SPS and vacuum induction melting were compared.It is shown that Mg_2-xNd_xNi alloys prepared by SPS exhibit a multiphase structure,demonstrating better hydrogen absorption/desorption kinetics performances but deterioration in hydrogen storage capacity with increasing Nd content,and Mg alloying is prompted by Nd.Sintering temperature has an obviously effect on the hydrogen storage capacity and the plateau properties of PCT curves.When Mg_2-xNd_xN alloys contain Mg or NdMg₁₂ phase,their PCT curves exhibit two platforms.Compared with the alloys prepared by casting,the Mg_1.7Nd_0.3Ni hydrogen storage alloy prepared by SPS has better absorption/desorption kinetics properties but awful hydrogen storage capacity,hydrogen desorption rate and platform properties of PCT curves.