Abstarct: In the recent years cadmium oxide (CdO) thin films due to their high transparency in the visible region and high conductivity have been extensively studied. Because of these properties, it is very good candidate for optoelectronic devices such as gas sensors, solar cells and photodiodes. CdO is a n-type semiconductor with rock-salt crystal structure which has direct and indirect optical band gap of about 2.2-2.7 eV and 1.9 eV, respectively. CdO thin films have been grown using variety methods, such as chemical bath deposition, DC magnetron sputtering; spray pyrolysis and sol-gel. In this thesis, pure and fluorine-doped CdO thin films were deposited on glass substrate, by sol-gel and spray pyrolysis techniques. The post-annealing treatments of the samples were performed in an electrical furnace under atmosphere ambient. For characterization of studied samples different measurements have been employed. X-ray diffractometry was used to identify the phases and the structure of each phase; transmittance measurements to determine the variation of the optical absorption coefficient versus wavelength, scanning electron microscopy to observe the surface topology and sample morphology and four point probe to determine the resistivity of the films. All films, which have been grown, were polycrystalline with cubic structure. We found that the films which were annealed in 350 oC, has maximum figure of merit. Thus, it can likely be the best annealing temperature to prepare high quality CdO thin films. Optical transmittance in visible region of this film was about 80%. Direct and indirect band gap values of the film were obtained 2.61 and 2.03 eV, respectively. The resistivity of the film was 0.52 Ω-cm. Although X-ray diffractometry showed that the sample was grown by spray pyrolysis has better structural quality, but the sample which was prepared by sol-gel method has higher optical transmittance. Study on the effect of rotational speed on the optical properties of CdO thin films deposited by spin sol-gel route, was indicated by increasing of the speed from 2000 to 3000 rpm, the direct and indirect band gap increase from 2.53 and 1.43 eV to 2.64 and 1.61 eV, respectively. Investigation of the effect of doping (up to 20 atomic percent) on optical properties of CdO films indicated the laxyer including of 15% fluorine content has a maximum figure of merit and optical transmittance in visible region of about 85%. The direct and indirect band gap values were calculated 2.64 and 1.98 eV, respectively. The electrical resistivity of the film was . Scanning electron microscopy shown that by increasing of the fluorine concentration, the grain size of the film decreased.