Abstract: Zirconia films were prepared by reactive RF magnetron sputtering method on （100） n-Si substrate. The relationships between oxygen partial pressure and deposition rates, surface roughness of ZrO₂ films, thickness of native SiO₂ interfacial layers, refraction index of ZrO₂ films were investigated. The results show that deposition rates of zirconia films decrease and film surface roughness increases approximately linearly with the increase of oxygen partial pressure. The thickness of native SiO₂ interfacial layers between zirconia film and Si substrate rapidly increases in a higher oxygen partial pressure but hardly changes in a lower oxygen partial pressure. The index of refraction of film samples deposited in the atmosphere of O₂/Ar mixing gas is almost independent of oxygen partial pressure, but the index of refraction of film samples deposited in pure oxygen ambient atmosphere is reduced, and the compactness of films becomes worse.