In the present study, titania (TiO2) nanoarrays were prepared by hydrothermally oxidating a titanium substrate in aqueous alkali and then postannealed at 300 degrees-550 degrees C for 2 h. The nanoarrays were composed of oriented one-dimensional nanowires or nanobelts. The growth mechanism of the nanoarrays was discussed by observing the structure under different synthesis conditions. The TiO2 nanoarray film was transferred to a transparent conductive glass substrate, used as a photoanode of a dye-sensitized solar cell (DSC). A light-to-energy conversion efficiency of 6.58% for the DSC was obtained.