Functionally gradient cathodes (FGC) realize the combination of ablation-resistant surface and conductive matrix, which can effectively extend the cathodic service life. Nb/Cu FGC, with Nb layer and Cu as surface and matrix, respectively, was prepared by laser cladding. The microstructure, composition, and the phase information were characterized. The microhardness and thermal conductivity of the FGC were tested. Furthermore, the cathodic discharge and ablation behavior in Ar atmosphere were investigated. Results show that several scattered cathode spots appear and densely distributed ablation craters are observed. The Nb/Cu FGC displays relatively moderate ablation behaviors. The average ablation rate of Nb/Cu FGC (1.61 μg/C) is 26.1% lower than that of Cu cathodes (2.18 μg/C), as ascribed to the synergy of ablation resistant Nb surface and the highly-conductive Cu matrix. Nb/Cu FGC exhibits the potential in arc plasma applications.