The vanadium oxide thin films are prepared by DC magnetron sputtering on normal glass. Then the samples are annealed at 450 ℃ in vacuum. The XRD pattern and the resistors of thin films are measured before and after annealing. And the effects of different sputtering time（120 min、100 min、60 min） on the properties of vanadium oxide films are compared. The results show that the degree of crystallinity of the films enhanced with the time extends. And the resistors of thin films are significantly reduced after annealing. The resistors of three thin films are 16.0 MΩ、65.0 MΩ、71.5 MΩ respectively. The sputtering time is longer; the resistance is smaller, while the temperature change in amplitude is smaller.