Amorphous Se100-x (Sn Sb)x glasses with (0 ≤ x ≤ 20 at. %) were prepared by the usual melt quench technique. Thin films for these compositions were prepared by thermal evaporation onto ultrasonically cleaned glass substrates kept at room temperature. From the spectral dependence of the absorption coefficient, a direct electronic transition was mainly responsible for the photon absorption inside these films. The effects of composition on the optical properties of Se100-x(Sn Sb) x thin films was investigated. The refractive index, n, for the as-prepared and annealed films has been analyzed according to the Wwmple–DiDominico single oscillator model. The effect of addition (Sn Sb) on the nature and degree of crystallization has been investigated by studying the structure using transmission electron microscope, X-ray diffraction and scanning electron microscope.