The La1+xMg2-xNi9(x=0,0.5,1.0,1.5)alloys were prepared in high frequency induction furnace under Ar atmosphere.The compositions and phase structures of the prepared alloys were analyzed by XRD method,and their hydrogen storage capacities and electrochemical performances were investigated.The results show that with La content increasing,LaNi5 and(La,Mg)Ni3 phases are transferred to LaNi3 phase,Mg2Ni phase appears,the cell volume increases,and the hydrogen storage capacity and electrochemical performance are improved.While x=1.5,Mg2Ni phase disappears,the hydrogen storage properties of La2.5Mg0.5Ni9 alloy are impaired.The hydrogen storage capacity and electrochemical performance of La2MgNi9 alloy are better than those of the other three alloys.