The geometry optimization, the electronic and magnetic properties of the compound Ni4NdB are studied by using first-principles within the local spin-density approximation (LSDA) and the LSDA+U approximation. The results indicate that the system is a metallic conductor with very small band gap, and that the total magnetic moment is provided by the local Nd magnetic moment. The system has very complex bonding, where Nd atoms and the neighboring Ni atoms form metal bonding, also Nd atoms and the neighboring B atoms form the strong ionic banding, besides Ni atoms and the neighboring Ni atoms forming an indirect exchange interaction. Under coulomb interaction, the system magnetic moment is consistent with that of the local Nd atom, and the collapse of magnetic ordering in 2.75 eV happens to the local Ni magnetic moment.