The demand of efficient energy storage devices is expected to grow substantially due to increasingly high use of portable electronic devices and hybrid vehicles. Supercapacitors are promising as they bridge the high energy density batteries and high power density based dielectric capacitors. The performance of a supercapacitor is largely dependent on the electrode material especially for an electrochemical capacitor which relies on the Faradaic redox reactions at the interface. In this work, a facile and simple hydrothermal method to grow NiCo2S4 particles of various sizes on porous g-C3N4 nanosheets was developed. Due to the excellent coupling and uniform distribution of NiCo2S4 nanoparticles on g-C3N4 nanosheets, g-C3N4/NiCo2S4 composite electrode material showed promising properties as an electrode material. The optimal material exhibited a high specific capacitance (752 A g-1 at 1 A g-1), superior cyclic stability and good rate capability. This enhanced performance as supercapacitor electrode material is attributed to the structure of g-C3N4 loaded with NiCo2S4 particles which provides short ion diffusion pathways and excellent ion permeability.