Four-, six-, and eight-membered ring silica nanotubes at temperatures from 300 K to 1600 Kare relaxed by classical molecular dynamics simulations with three potential models. Thesimulation results indicate that the stability of the end rings of the three silica nanotubes gradually decreases with increase in temperature. The validity of the vibrational features of silica nanotubes is shown by the vibrational density of states. Infrared spectra on the silica nanotubes under different temperatures are investigated. A detailed assignment of each spectral peak to the corresponding vibrational mode of the three nanotubes has been addressed. The results are in good agreement with the other theoretical and experimental studies.