Core shell structure carbon encapsulated NiO nanoparticles were successfully prepared by DC arc discharging plasma technology. The micstructure of the samples were studied by X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), X-ray energy dispersive spectrometry (XEDS) and Surface physical adsorption. The cyclic voltammetry, galvanostatic changing-discharging and electrochemical impedance spectroscopy were investigated to characterize the electrochemical performances of the composites as the electrode materials for super-capacitors. The experimental results indicate that the carbon encapsulated NiO nanoparticles prepared by DC arc plasma technology possess typical core shell structure, the core of the particles is NiO with face centered cubic structure, and the outer shell is disordered carbon layer. The particle morphology exhibit cube structure with uniform particle size and good dispersion. The particle size distribution is in the range of 30-70nm, the average particle size is 50nm, and the thickness of the carbon shell is about 5nm. Carbon encapsulated NiO nanoparticles has high specific capacity and good electrochemical activity.