Photorewritable conducting polyaniline (PAn) image was successfully obtained by the photopolyrmerization of aniline derivatives with Flemion polyelectrolyte composite film containing Ru(bpy)(3)(2+) and TiO2. The image can be erased and regenerated by consecutive photoreduction and photooxidation via photoinduced electron transfer for TiO2 and Ru(bpy)(3)(2+) in the polyelectrolyte composite film, respectively. These photoinduced reactions were considerably affected by the deaeration condition for the reaction solution. When the photooxidation and photoreduction were carried out in the reaction solution deaerated with O-2 and N-2, respectively, good reversibility was obtained on the present system. However, the decomposition of the PAn was observed by excessive photooxidation in the acidic aqueous solution due to the hydrolysis of the PAn. In order to prevent the PAn decomposition, photoredox reaction of the PAn polyelectrolyte composite film was investigated in dichloroethane containing CF3COOH and MeOH. Consequently, improvement of photoreduction efficiency, as well as inhibition for the decomposition reaction of the PAn polyelectrolyte composite film was obtained. (C) 2000 Elsevier Science Ltd. All rights reserved.