A nitrogen-doped electrospun reduced graphene oxide-carbon nanofiber composite (NG-CNF) was fabricated via electrospinning by adding graphite oxide into a precursor solution and subsequent thermal treatment under an ammonia atmosphere. The morphology, structure and electrochemical performance of the composite were characterized by scanning electron microscopy, nitrogen adsorption-desorption, cyclic voltammetry and electrochemical impedance spectroscopy, and their capacitive and electrosorption performances in NaCl solution were studied. The NG-CNF composite electrode shows excellent specific capacitance (337.85 F g(-1)) and electrosorption capacity (3.91 mg g(-1)), much higher than those of pure carbon nanofibers (171.28 F g(-1) and 3.13 mg g(-1)) and the reduced graphene oxide-carbon nanofiber composite (264.32 F g(-1) and 3.60 mg g(-1)). The enhanced performance of the NG-CNF is ascribed to the nitrogen doping and the formation of an effective "plane-to-line" conducting network in the composite, which facilitates the electron transfer and ion transport as well as increases the specific surface area.