A composite electrode based on polyaniline (PANI) and hydrous RuO2 is prepared by electrochemical deposition of PANI onto hydrous RuO2 (PANI/RuO2) and its supercapacitive properties are investigated using cyclic voltammetry. The specific capacitances of PANI/RuO2 and hydrous RuO2 electrodes are determined to be 708 and 517 F g(-1) at 5 mV s(-1), respectively. Simple electrodeposition of PANI on the hydrous RuO2 can achieve comparatively greater capacitance values.