ZrO2 is an important material used in high laser damage coatings. Influence on the microstructure of ZrO2 thin films deposited at different O2 partial pressure and substrate temperature was analysed by X-ray diffraction (XRD) technique, the surface roughness and laser damage threshold also were measured. The results showed that morphology transition from polycrystalline to amorphism occurred with O2 pressure increaed while from amorphism to polycrystalline occurred with substrate temperature increased. Simultaneously, it was found that the grain size was reduced with the increased O2 pressure but increased with the increasing substrate temperature. The surface roughness was improved with increasing O2 pressure but has little change with substrate temperature increased. The change of grain size have some relationship with the surface roughness. The damage results indicated that O2 pressure and substrate temperature can influence the laser damage threshold of ZrO2 thin films.