Optical property and crystallinity of Ge(90)Te(10) films prepared by electron beam evaporation have been studied. The films grown at different substrate temperatures (Ts) and deposition rates (R) have been characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and spectroscopic ellipsometry. The polycrystalline film was obtained at Ts = 300 degrees C, while the amorphous film was obtained when Ts <= 200 degrees C. However, the film showed the columnar structure when Ts <= 100 degrees C. It was found that Ts had the stronger effect on the crystallinity of the film rather than R. The optical constant in the infrared region was determined. All the film exhibited no absorption, but the refractive index was varied with the change of Ts and R. The relationship between optical constant, the film structure and the deposition parameters were also discussed. In addition, the optimum deposition condition of Ge(90)Te(10) film was found. (C) 2010 Elsevier B.V. All rights reserved.