ZrO2 sol was prepared by sol-gel process from a solution containing zirconium n-propoxide as precursor, hydrochloric acid, PVP and acetylacetone as complexing agent in ethanol. The characterization of ZrO2 sol and films was analyzed by viscosity, infrared (IR) spectroscopy, refractive index, differential scanning calorimetry (DSC) and atomic force microscopy (AFM). The results show that the ZrO2 sol has a good viscosity stability. The influence of PVP on sol-gel stability is little. The refractive index of coatings treated at 500 ℃ is 1.91. The morphology of coatings surface is smooth. The laser induced damage threshold (LIDT) of coating is improved by adding PVP from 19.6 J/cm2 (1064 nm, 1 ns) to 23.3 J/cm2 (1064 nm, 1 ns).