Abstract: The CuInSe2 (CIS) thin films were prepared by tri-source vacuum co-evaporation with the pure Cu, In and Se powder as the evaporation sources. The effects of substrate temperature and annealing process on the surface morphology, structure and optical electrical properties of the films were investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD), UV-visible spectroscopy and Hall probe. The results showed that the absorption indices of the thin films deposited on the substrates at different temperatures are all high in visible light band and all the films have a (112) preferred orientation. The energy gap is 0.99 eV when the substrate is at 200°C. The CuInSe2 films are of single chalcopyrite structure when the substrate temperature is either 200°C or 300°C, and their resistance is 1.53 Ω/cm² or 1.55 Ω/cm² after annealing, respectively.