Abstract: The influence of laser surface heat treatment on fatigue properties is investigated for the rolled polycrystalline copper thin films in this paper.The aim is to find optimal conditions of treatment,which will extend the material resistance to fatigue failure,and explore the mechanisms of fatigue fracture and surface micro-structure,by changing the laser process parameters.Results show that scanning speed and power density of laser treatment have greater influence on the fatigue life of specimens,which is more than two to three times the original specimens life at laser power density of 208 kW/cm²,laser scanning speed of 25 mm/s for 25 μm thick rolled polycrystalline copper thin films.SEM observation results for fracture surface show that the hardened layer and the residual compressive stress are formed on the surface area of specimens,which makes the fatigue strength of specimens significantly increase.Since the crack growth rate for laser heat treatment specimens is slower than that of the original specimens,some fatigue striations are formed in the fatigue propagation region.