Based on the model of the two phases of grain and grain boundary, the grain boundary tunneling of carriers was considered to simulate the change of the resistivtiy of VO₂ polycrystalline film prepared by Sol-gel method in temperature range of 10℃～100℃.The simulation results were in good agreement with the experiment data. The results indicate that the grain boundary effect decreases the magnitude of resistivity change of VO₂ film durying semiconductor-to-metal phase transition, and meanwhile the VO 2 film in metal phase has a negative temperature coefficient of resistivity.