With mesoporous carbon (CMK-3) serving as a support, we prepared a novel nanocomposite of polypyrrole/mesoporous carbon (PPy-CMK-3) by an in situ chemical polymerization method. An electrochemical hybrid capacitor was successfully designed using a PPy-CMK-3 composite and CMK-3 as positive and negative electrodes, respectively. The electrochemical capacitance performance of this kind of hybrid capacitor was investigated in 1.0 mol·L-1 NaNO3 electrolyte solution. The discharge capacity of the hybrid capacitor reached 57 F·g-1 under a current density of 5.0 mA·cm-2 and cell voltage of 1.4 V. The energy density of the hybrid capacitor reached 17 Wh·kg-1 with a power density of 2.5×102 W·kg-1. When the current density was increased from 5.0 to 50 mA·cm-2, the capacity of the hybrid capacitor remained at about 80% and it showed excellent high rate charge-discharge performance. Furthermore, the PPy-CMK-3/CMK-3 hybrid capacitor containing this PPy-CMK-3 nanocomposite could be active easily and it possessed a high charge-discharge efficiency and od cycle performance.