Abstract: Polyaniline (PANI)/RuO₂ composite electrodes were prepared by coating thermal decomposition and electrochemistry polymerization procedures. RuO₂ film was synthesized by coating thermal decomposition method at 260℃ for 3 h, and PANI particles were deposited on RuO₂ films and dried at 80℃ for 12 h. The formation of the amorphous phase of PANI/RuO₂ composite was studied by XRD. Morphologic variations of the composite electrodes were established by SEM. Electrochemical performances of the composite electrodes were measured by cyclic voltammetry (CV) and galvanostatic charge-discharge. The results show that when the deposition time of PANI is 25 min, the maximum capacitance and the specific capacitance of PANI/RuO₂ composite electrode is 9.72 F and 452 F·g^-1 respectively. Charge-discharge curves of the composite electrodes illustrate low potential drops, internal resistances and good charge-discharge properties. Approximately 11% loss of capacitance is observed after 1000 CV cycles.