Abstract: In the present study，the commercial activated carbon(AC) as electrode material used by electric double-layer capacitor(EDLC) were modified through physical method.The experiment was carried out in a vibration mill.The resultant activated carbon was characterized by BET surface area, pore size, pore volume and electrochemical performance.BET surface area increased from 1739.77 m²•g^-1 to 2215.40 m²•g^-1 after modification,micro-pore surface and mesopore increased 22% and 35% respectively and pore volume increased by 20%—30%.Both high pore volume and more rational pore distribution of active carbon contributed to better electrochemical characteristics.The modified activated carbon increased the specific capacitance of electrode by 10%, up to 424 F•g^-1.