Vanadium oxide films are prepared by Sol-Gel at different annealing temperatures. Their surface morphologies, valence states, electrical and optical properties are characterized by SEM, XRD, resistance meter, UV-Vis spectrometer and FTIR, respectively. Results reveal that the optimal temperature for producing V2O5 films by Sol-gel is 430 ℃, the organics in the films cannot be decomposed completely below 430 ℃ while the V-O bonds will be broken under a higher temperature (>430 ℃). The as-prepared vanadium pentoxide films exhibit higher TCR and larger light absorption, so that they are suitable to be used as bolometric materials for uncooled infrared detectors. The growth mechanism of vanadium oxide film prepared by Sol-Gel is also presented in this paper.