The electrical conductivity of the polypyrrole/(anion containing copolyester) composite Films prepared from FeCl3-copolyester surface adsorption was investigated. Copolyester films prepared by dipping in FeCl3 solutions were exposed to pyrrole vapor. FeCl3 solutions were prepared from phenol/TCE and methanol mixtures with three different mixing ratios (phenol/TCE:methanol), that is, 1:1, 2:1, and 3:1. The composite films prepared from the 3:1 and 2:1 solutions showed higher conductivity than those prepared from the 1:1 solution. The Fe content of the films was found to br closely related to the conductivity of the composites. The conductivity of the composite films showed the highest value when DMS, the ionic group, content in the copolyester was 6 mol% for all the solvent compositions examined.