Nanotube-shaped powders had been synthesized successfully from commercial anatase-type titanium dioxide powder by ion exchange approach. All nanotubes were open-ended with 3 similar to 5 nm in inner diameter, 8 similar to 12 nm in outside diameter and 200 similar to 400 run in length. EDS result revealed that the nanotube was only composed of Ti and O. XPS analysis showed that two peaks located at 458.5 and 464.2 eV were assigned to Ti4+ in titanium dioxide. The formation mechanism of titanium dioxide nanotubes was also discussed in this paper.