Abstract: The present invention provides a water-soluble self-acid-doped polyaniline blends, comprising a 70-90% weight percentage polyaniline derivative and 10-30% weight percentage at least a water-soluble polymer. The blend can be used to produce a conductive polymer film and/or a conductive-polymer composite film. In the present invention, a water-soluble self-acid-doped polyaniline derivative is blended with a water-soluble polymer to enhance the mechanical properties and the coating-to-substrate adhesion of the electric conductive polymer film or the electric conductive-polymer composite film, and increase the conductivity of the blender. In addition, the blend containing a water-soluble self-acid-doped polyaniline of the present invention is biotoxicity-free and has free radical-capture capability. Thus it can be used as a biocompatible and conductive biomedical material.