Zirconium oxide (ZrO2) coatings for 632.8nm center wavelength were deposited on the Ag layer by electron beam evaporation, optical thickness of which varied in the range of 80—480nm. Surface roughness and scattering characteristics of ZrO2 coatings with different thickness were investigated. It was found that with the gradually increase of the thickness, both roughness and total integrated scattering (TIS) of the samples decreased firstly and then increased. These results indicated that TIS of the samples mainly depended on the surface roughness. According to the uncorrelated surface roughness scattering model, scattering properties of the samples were analyzed theoretically. The calculated TIS values based on this model agreed well with that obtained by TIS measurements.