The rare earth-transition (R-T) intermetallics has excellent physical and chemical properties. The electronic structure, the band structure and the magnetic properties of the compound Ni13Nd3B2 are studied by using the first-principles plane wave pseudopotential method and the local spin-density approximation (LSDA). The calculation results indicate that this system is a metallic conductor with a very small band gap. The system has very complex bonding, where Nd atoms and the neighboring Ni and B atoms form ionic banding, whereas Ni atoms and the neighboring Ni atoms form covalent bonding. Under LSDA approximation, the system has Nd-Ni ferromagnetic coupling, and the total magnetic moment ( 8.4329B) is provided by the local Nd magnetic moment. The Nd-4f, Ni-3p, Nd-5p electron spin splittings due to spin polarization result in the magnetic system.