Abstarct: In this thesis we have studied the surface morphology and structural and optical properties of intrinsic and MoO3 doped tungsten oxide (WO3) samples. In order to grow thin films, spray pyrolysis and hydrothermal route have been utilized. For characterization of samples field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD) and UV-Vis spectroscopy techniques were used. Studied parameters in spray pyrolysis technique are including: substrate temperature (300-350-400-450 and 500 ℃), concentration of the precursor solution (0.01, 0.02, 0.04, 0.08, 0.1 and 0.2 M), volume of the precursor solution (50, 100, 150 and 200 mL), pulse spray pyrolysis in different concentrations (0.01, 0.1 and 0.2 M) and finally the effect of doping samples with MoO3 in different percentage (1%, 10%, 20%, 40%, and 50%). FESEM images shows the formation of micro-fibrous reticulated surface morphology with a uniform distribution, which forms in the shape of nanoplates with increasing in the percentage of doping. The XRD patterns for undoped and lightly doped samples shows no structure and are amorphous, with increasing in the amount of dopping and also increasing the molarity of precursor solution, samples show polycrystalline structure. Transmission spectra of the samples indicate that all of them are transparent in the visible range with calculated direct band gap of about 3.3 eV. In the hydrothermal route bare glass and spayed seed laxyers on top of glass were used as substrates. In this part of work the effect of different substrate, surfactants and hydrothermal process time. Results show the formation of monoclinic and hexagonal crystal structures. FESEM images of the samples indicate the formation nonoplates.