ZrO2-Y2O3 films with different Y2O3 concentrations have been prepared by rf magnetron reactive sputtering. The films have been characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), Raman spectroscopy and optical spectroscopy. The influence of Y2O3 concentration on the microstructure and the optical properties have been discussed. Both tetragonal and cubic symmetries with a preferred orientation along (200)(c,t) plane are found. The crystallite size increases with the increasing of Y2O3 concentration. It can be found that the refractive index and the extinction coefficient decrease with increasing of Y2O3 concentration.