Transparent, conductive and uniform graphene films have been prepared and used as electrodes of the electrochromic devices of polyaniline. Polyaniline films on both graphene and the widely used indium tin oxide (ITO) electrodes showed similar electrochemical and spectroelectrochemical properties. However, graphene electrodes exhibited much higher electrochemical stability than ITO in aqueous acidic electrolytes. The performances of the electrochromic devices with graphene electrodes exhibited slight decrease upon voltage switching while those of the devices with ITO electrodes decreased dramatically. After 300 cycles, the electrochromic devices with graphene electrodes showed much larger optical contrast and shorter switching time than those of the devices with ITO electrodes. (C) 2009 Elsevier Ltd. All rights reserved.