Graphene-composited TiO2 photoelectrodes are prepared by hydrothermal method. The influences of different amount of graphene on the structures and properties of the dye-sensitized solar cells (DSSCs) are studied and an optimal graphene-composited DSSC is obtained. Studies indicate that compositing of graphene can effectively enhance the open circuit voltage, short circuit current density, and photoelectric conversion efficiency (eta) of the DSSCs. Furthermore, the eta of the DSSC with the optimal graphene-composited TiO2 film is 7.02 +/- 0.06%, significantly higher than that of the pure TiO2 DSSC. These improvements can be attributed to the increased dye absorption due probably to the increase of the photoelectrode films' specific surface area and the good conductivity of graphene. (C) 2014 Elsevier Ltd. All rights reserved.