Highly porous N-doped CNTs/Fe₃C was synthesized by a facile and one-pot method. In this method, melamine was used as the carbon precursor; iron chloride was employed as a catalyst of graphic carbon and iron carbon source, and zinc chloride as a chemical activator to obtain highly porous structure. Fe₃C nanorods were in situ formed and embedded into the inner structure of CNTs. The pore structure analysis shows that N-doped CNTs/Fe₃C possesses the large specific surface area up to 1021.26 m² g⁻¹. The N-doped CNTs/Fe₃C electrode exhibits a high specific capacitance of 181 F g⁻¹ at the current density of 0.1 A g⁻¹, and excellent capacitance rate and cycling stability.