Abstract: Cold gas dynamic spraying characteristics and process principle were introduced.Cu coating microhardness and bonding strength were tested.Microstructure, phase structure, stress state and micro-region composition of Cu coating were analyzed by SEM, XRD and EDX.Results showed that the average microhardness is higher than that of bulk copper.The bonding strength is higyh between the coating and the base metal.The results of XRD shows that there is no oxidation and changes of phase stracture in Cu coating. The stress of coating is mainly compressive stress, which help to improre the bonding strength.After aging at 300℃, interface between the coating and the base metal appears diffusion layer.