Amorphous Mg2Ni-based alloy powder was prepared by sintering and subsequent ball milling with Ni. The effects of substitution of Mn for Mg on phase formation and electrochemical discharge performance of Mg2Ni-typed alloys were studied. The results show that partial substitution of Mn for Mg in Mg2-xMnxNi (x=0.1,0.2,0.3,0.4) alloys can obtain homogeneous amorphous alloys and can increase the discharge capacity effectively compared with Mg2Ni alloy. As the content of Mn substitution increases, the maximum discharge capacity and rate discharge capability of Mg2Ni-typed alloy decline and the cycling durability upgrades.