ZnTe and ZnTe∶Cu polycrystalline films were fabricated by means of co-evaporating at room temperature. The sturcture and distribution of various elements were studied by XPS and XRD. The XRD results show that the phase structure of the films deposited at different substrate temperature almost remains unchanged, XPS analysis shows that the compositional dependence of sputtering time is different for the films deposited at different deposition rate. The distribution of Cu in the film grows with the increase in the sputtering time, and reaches a maximum, then falls down rapidly. According to the transformation of the distribution of Cu we excogitated how to prevent Cu diffusion in ZnTe films. Considering Cu as a function of time, ZnTe films were first deposited at the substrate temperature of 70 ℃, and then ZnTe∶Cu films were deposited at room temperature, effectively preventing the diffusion of Cu atom, and thus improving the efficiency of CdTe solar cells.