A TiO2 nanotube array with a large surface area is fabricated on a glass substrate using a ZnO nanorod array and sol-gel process, and the structural characteristics of the TiO2 nanotube array are investigated. The well-aligned ZnO nanorod array, which is deposited on ZnO seed layer coated glass substrates by the wet-chemical route, is used as a template to synthesize TiO2/ZnO composite nanostructures through the sol-gel process. Then, by selectively removing the ZnO template, a TiO2 nanotube with contours of the ZnO nanorods is fabricated on the ZnO seed layer coated glass. The resultant TiO2 nanotubes are 1.5 mu m long and 100-120 nm in inner diameter, with a wall thickness of similar to 10 nm. In addition, by adjusting the experimental parameters, such as the dip-coating cycle number or heating rate, porous TiO2 thick films can also be obtained.