Titanium oxide nanotube (TiO2 nanotube, TNT) is synthesized by the low-temperature solution chemical method via the self-organization to form unique open-end nanotubular morphology with typically 8-10 and 5-7 nm in outer and inner diameters, respectively. Because of the mutual and synergy combination of its low-dimensional nanostructure and physical-chemical characteristics of TiO2 semiconductor, properties enhancements and novel functionalization are expected in the TiO2 nanotube. In this chapter, synthesis, nanostructures, formation mechanism, various physicochemical characteristics, and prospects of future application for the TiO2 nanotube are described in detail. In such an oxide material, property control and enhancement is possible by tuning appropriate chemical compositions, crystal structures, and composite structures. Therefore, special emphasis is also placed to introduce modification of the nanotubes by doping and/or nanocompositing to meet the requirements as for the environmental friendly and energy creation systems and various functional devices.