TixSn1-xO2 films with gradient composition profiles have been prepared by the liquid phase deposition method. The crystal structure and composition of these TixSn1-xO2 films were investigated by means of high-resolution transmission electron microscopy (HRTEM) and energy dispersive X-ray (EDX) analysis with a nano-probe. The gradient profile of the films in the direction of film thickness could be controlled by varying the flow rate. The existence of microcrystalline rutile-SnO, and anatase-TiO2 was observed near the substrate and the top-surface, respectively. The photocatalytic activity of TixSn1-xO2 films with gradient composition profiles was markedly higher than that of the SnO2/TiO2 multilayer. (c) 2004 Elsevier B.V. All rights reserved.