The preparation of nanoporous TiO2 electrodes modified with CaTiO3 layers and their application in dye-sensitized solar cells (DSSCs) were reported. The as-prepared TiO2/CaTiO3 electrodes were characterized by XPS and XRD, indicating that a thin CaTiO3 layer was formed on the surface of nanoporous TiO2 electrodes. Compared with bare TiO2 electrodes, CaTiO3 modified TiO2 electrodes presented more dye adsorption. Moreover spectroelectrochemical studies showed that the concentration of free electrons in the conduction band of TiO2 was remarkably increased after surface modification. As a result, the photocurrent and photoelectric conversion efficiency of the modified electrodes were increased. The influence of the thickness of CaTiO3 layer on the photoelectrochemical properties of the modified electrodes was investigated. Experiment results showed that proper thickness of the modification layer is crucial to the photoelectrochemical properties of modified electrodes. The highest conversion efficiency reaches 9.23% under irradiation of 100 mW cm(-2) white light, obtained with the electrode TiO2/CaTiO3(45 min), a 34% increase than that of bare TiO2 electrodes. (C) 2009 Elsevier Ltd. All rights reserved.