Three dimensional carbon materials with hirerarchically porous structure could exhibit superior energy storage performance than two dimensional stacked carbon nanosheet materials. In this work, we prepared a novel ZIF-8-derived nitrogen doped carbon nanoparticles/graphitic carbon nitride composite electrode material with high electrochemical energy storage performances, including high specific capacitances (495 F g(-1) at 0.1 A g(-1) and 188 F g(-1) at 20 A g(-1)) and a stable cycling durability with no capacitance declination after 5000 charge-discharge cycles in three-electrode system. When assembled as electrode materials in symmetrical two-electrode system, the as-prepared composite electrode material could exhibit high specific capacitances of 349.7 F g(-1) at 0.5 A g(-1) and 261.2 F g(-1) at 5 A g(-1). Accordingly, a high energy density of 11.89 Wh/kg can be achieved at the power density of 247.40 W kg(-1). The improvement stems from its hierarchically porous structure with dominant pore sizes at 3 nm and among 4-40 nm, as well as high exposed pyridinic nitrogen (8.58 at%) and pyrrolic nitrogen (3.59 at%) active sites caused by the insertion of ZIF-8-derived nitrogen doped carbon nanoparticles between g-CN layers. This study has provided a new idea on the design of graphitic carbon nitride nanostructures with improved doping level and hiearchically porous structure. (c) 2018 Elsevier Ltd. All rights reserved.