Abstarct: In this study, TiO2 nanostructured thin films were prepared by spray pyrolysis method. The spray solution was contained of titanium tetra-isopropoxide (TTIP) as the precursor and pure ethanol as the solvent. The prepared precursor was then sprayed on to glass substrates. Here, we have tried to study the effects of precursor concentration, substrate temperature and annealing on the structural, optical and electrical properties of these samples. For characterization of the synthesized samples we used various apparatuses including: Field Emission Scanning Electron Microscopy (FESEM), X-ray diffraction (XRD), Raman spectroscopy, and ultraviolet-visible (UV-Vis) spectroscopy. In the first step (section 4-2) TiO2 nanostructures with different volumes ratios of TTIP to pure ethanol as 1:1, 1:2 and 1:3 in a volume of 15 ml were deposited on glass substrates at 385 ºC. From the characterization of the samples it was revealed that only sample synthesized with higher concentration has an anatase crystalline phase with preferential orientation (101) while other samples are amorphous. Considering this fact we then in section 4-3 used the corresponding deposition condition to investigate the impact of substrate temperature (385, 425 and 475 ºC). The data analysis showed that with increasing the substrate temperature the surfaces of the laxyers have lower porosity, and thinner thicknesses. In addition, the structural analysis showed the laxyers became amorphous. In the final step (section 4-4) the annealing process was acted on these samples in vacuum and also in nitrogen gas flow (20 sccm) at 550 ºC for 2 h. In general in was revealed that annealing in vacuum has improved the crystallinity of the laxyers, and in N2 ambient has considerably affected on surface morphology of the laxyers.