Abstract: Porous graphene thin sheets (p-Gr) doped with nitrogen are prepared from graphene oxide (GO) by using ammonium sulfate ((NH₄)₂SO₄) as dynamic gas template. The obtained samples are characterized by SEM, TEM, XRD, XPS, Raman, and N₂ adsorption-desorption. Furthermore, the influence of different (NH₄)₂SO₄ dosages on the electrochemical performance of the corresponding samples is investigated. Compared with the un-activated graphene (Gr) (S_BET=70.5 m²/g), the resultant p-Gr-40 possesses higher specific surface area (S_BET=267.3 m²/g), more abundant porous structure, and much better capacitive performance. The specific capacitance of p-Gr-40 (C_m=139.2 F/g) is much larger than that of Gr (C_m=56.5 F/g) at a current density of 1 A/g in the three-electrode supercapacitor system. Meanwhile, p-Gr-40 owns an energy density of 12.98 Wh k/g at the power density of 160.03 W/kg in the two-electrode supercapacitor system. Also, the initial capacity retention of p-Gr-40 is nearly 100% even after 10 000 charge-discharge cycles at 1 A/g, demonstrating its excellent cyclic stability. The enhanced electrochemical performance is contributed by the porous structure and heteroatoms doping (such as nitrogen).