The vanadium oxide thin films are fabricated for microbolometer by radio frequency reactive sputtering at room temperature. The effects of the oxygen partial pressure on deposition rate, electrical properties and compositions of the films are discussed. Films consisting mainly of VO2 can be prepared by adjusting oxygen partial pressure. After oxidation annealing in air, the VO2 films with high temperature coefficients of resistivity (about -4%/℃) and low resistivity can be obtained. The square resistances of the films are in the range between 100 kΩ/squ to 300kΩ/squ. All films are deposited at room temperature and annealed at 400℃, which is compatible with MEMS (micro electromechanical systems) process.