Abstract: The Cu thin films were deposited on P-Si（111） substrates by magnetron sputtering at room temperature.The surface morphology,nucleation and growth of Cu thin films on silicon were studied by growing a series of samples with different predetermined deposited times,which was followed by observation with Atomic Force Microscope（AFM）.Cu nuclei grew on silicon follow the Volmer-We ber mode when Cu films deposited by magnetron sputtering.In the process of deposition,nuclei grew into islands,then the islands connected to form channels,and finally formed continuous films.The roughness of Cu film surfaces increased due to the agglomeration and coalescence of Cu grains during deposition.The roughness decreased when then continuous and compact films with a degree of crystallinity were formed.