Abstarct: In this thesis, nanostructured CuInS2 (CIS) films were grown on various substrates including glass, ITO, FTO, and AZO using solvothermal and spray pyrolysis. The structural, morphological and optical properties of the films were characterized by XRD, Raman, FESEM and UV-Vis analyses. Investigation in structural properties of the CIS nanostructured films were grown directly on FTO using solvothermal method at different precursors including sulfuric acid, oxalic acid, and surfactant (separately) confirmed the formation of tetragonal CIS structure. The morphology examination of the surfactant-containing sample confirmed the formation of CIS nanostructures. The study of the optical properties of the samples showed that the bandgaps of the films were direct, and in the range of 1.24-1.56 eV. The pure sample (without the presence of acids and surfactant) had the highest bandgap (1.56 eV) and the sample containing the surfactant had the lowest bandgap (1.24 eV). Investigation of the structural properties of CIS films synthesized on the mentioned substrates (glass, ITO, FTO, and AZO) by spray pyrolysis with deposition rate of 2 ml/min and 370 °C substrate temperature, showed that the films were amorphous and annealing treatment at 400 °C and 450 °C for 1 hour in the laboratory atmosphere had no significant effect on the films’ structures. Increasing the deposition rate to 5 ml/min (same substrate temperature: 370 °C) also did not cause a noticeable change in the structural properties of the films. However, the study of the structural properties of the films synthesized at 5 ml/min deposition rate at 300 °C confirmed the formation of CIS tetragonal nanostructure on the various mentioned substrates. Optical examination of the samples showed that the film synthesized on glass/AZO had the highest transmission (minimum thickness: 1.3 µm)/ lowest transmission (highest thickness of 3.6 µm), respectively. The absorption coefficients of the films were also large in order of 104 cm-1. The bandgap values of the samples were in the range of 1.23 - 1.49 eV. The values of the bandgap, as well as the film's absorption coefficient values, showed that the synthesized samples are suitable candidates for using in the solar cells as an absorber laxyer. To further work, the synthesized CIS films were annealed at 500 °C under vacuum to improve the structural properties. However, X-ray diffraction patterns of the annealed samples showed that this treatment weakened CIS tetragonal phase.