The N-doped porous carbon (HPNCs) are prepared via facile carbonization of zeolitic imidazolate frameworks (ZIF-8) by controllable synthesis and appropriate temperature. In this work, we have discussed different pre-paradon methods and conditions about HPNCs. The material which is carbonated at 800 degrees C and used zinc acetate during preparation process exhibits excellent electrochemical performance with a high specific capacitance of 245 F g(-1) in 6 M KOH electrolyte at a current density of 1 A g(-1) and low resistance. Moreover, the symmetric supercapacitor of HPNCs-C8//HPNCs-C8 exhibits a special energy density about 24.8 Wh kg(1) at the power density of 0.79 kW kg(-1) in the wide voltage region of 0-1.8 V. Such outstanding electrochemical behavior shows that the HPNCs-C8//HPNCs-C8 symmetric supercapacitor is a promising practical energy-storage facility.