Poly(3,4-ethylenedioxythiophene)/polypyrrole composite electrodes were prepared by electropolymerization of 3,4-ethylenedioxythiophene (EDOT) on the surface of polypyrrole (PPy) modified tantalum electrodes. The electrochemical capacitance properties were investigated with cyclic voltammetry (CV), galvanostatic charge-discharge and electrochemical impedance spectroscopy (EIS) techniques with two- or three-electrode cell configuration. The data showed that the specific capacitance of composite electrodes, due to the synergic effect of poly(3,4-ethylenedioxythiophene) (PEDOT) and PPy, is much higher than the values of either pure PEDOT or pure PPy electrodes. Moreover, the composites prepared on the surface of PPy with horn-like structure allow the specific capacitance up to more than 200 F g(-1) and have a good cycleability. This implies that PEDOT/PPy composites are promising to be used as electrode material of supercapacitors. (c) 2006 Elsevier B.V. All rights reserved.