The electrochemical polymerization of thiophene in an ultrasonic field was performed with a view to obtaining polythiophene film with a high electrical conductivity. The conductivity, polymer yield, and morphology of a film were greatly affected by the polymerization temperature, monomer concentration, and current density. The larger the current density was, the higher the electrical conductivity and the lower the yield were obtained. Also the film surface becomes less uniform. In contrast, the higher the polymerization temperature was, the higher the yield and the lower the electrical conductivity were obtained. Since the polymerization temperature appeared to be the most dominant among the factors affecting the conducting polymer film''''s properties, the polymerization was performed at 5℃, 15℃, and 25℃ to examine the temperature effect. Ultrasound irradiation produced substantial positive effects on the conductivity and the morphology of the polythiophene film. The conductivity and the surface homogeneity were much improved. These results may be attributed to the fact that the ultrasound enhanced the mass transfer of the reactants and caused high chemical reaction rates by forming high temperature and pressure cavitations.