The polyaniline (PANI) electrodes are prepared by chemical synthesis and electrodeposition methods and their supercapacitive properties are characterized and compared by morphology observation, cyclic voltammetry as a function of scan rate, and impedance spectra analysis. In particular, the supercapacitive properties obtained in the range of higher potential scan rates (e.g., over $200mV;s^{-1}$) are emphasized to be capable of utilizing adequately the high power capability of supercapacitor. As a result, the PANI electrode by the electrodeposition shows superior specific capacitance (max. $474F;g^{-1}$ at $10mV;s^{-1}$ and about $390F;g^{-1}$ at $500mV;s^{-1}$) than those by the chemical synthesis method. This is mainly due to highly porous structure obtained by the electrodeposition to yield higher specific surface area.