A conducting polymer composite was prepared by the postpolymerization of pyrrole in a polyacrylonitrile (PAN) matrix film. To enhance the electrostatic interaction between the two phases, a small amount of a sulfonate (SO3-) or a carboxylate (COO-) group was incorporated into the PAN structure. The presence of electrostatic interaction between the conducting polypyrrole and the anion-containing PAN copolymer was elucidated by examination of the morphology and the electrical properties of the composite. The aromatic sulfonate-containing matrix provided the composite with the best results in the electrical conductivity, the environmental stability of conductivity, and the morphological property.