Amorphous and nanocrystalline Mg-based alloys (Mg60Ni25)(100-x)Nd-x (x = 2, 5, 10, 15) were prepared by rapid solidification. The microstructure of the as-quenched ribbons was characterized by TEM, X-ray and electron diffraction. The electrode properties of these alloys were measured. The experimental results showed that the discharge capacities increased with increasing Nd atomic content and the optimum Nd content is between in 10-15 mol%. The highest discharge capacity reached more than 580 mAh g(-1) at the discharge current densities of 50 mA g(-1) for (Mg60Ni25)(90)Nd-10 samples. The nanocrystalline (Mg60Ni25)(98)Nd-2 alloy showed the lowest discharge capacity compared to the other Mg-Ni-Nd amorphous alloys. The alloy (Mg(6)oNi(25))(90)Nd-10 displays the broadest discharge potential flat from 1.3 to 1.0 V. It was conformed that the increase of discharge capacities is not only a function of the sample composition but strongly influenced by the amorphous phase proportion in the alloys. (c) 2006 Elsevier B.V All rights reserved.