Rare earth-Magnesium-Nickel-based hydrogen storage alloys with superstructure have attracted intensive interests as the next-generation negative electrode materials of nickel/metal hydride (Ni/MH) batteries due to their high hydrogen storage capacity and high rate dischargeability. From the point of view of the correlation between phase structure, hydrogen storage characteristics and electrochemical properties, the state-of-arts of the R-Mg-Ni-based AB3, A2B7 and A5B19-type hydrogen storage electrode alloys were reviewed. It is expected to be helpful for exploring novel rare earth-based hydrogen storage electrode alloys with high discharge capacity and long cycling life.