Abstarct: In this research, zinc oxide (ZnO) nanostructured thin films were prepared by spray pyrolysis method. The precursor was prepared using zinc acetate dehydrate (C4H10O6Zn + 2H2O) as the main material and distilled water. The prepared precursor was then sprayed on to glass substrates. Here, we have tried to study the effects of precursor volume, adding nitrogen as the impurity, and finally the influence of 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), current-voltage (I-V) characterization, Hall effect, Seebeck effect and ultraviolet-visible (UV-Vis) spectroscopy. In the first step (section 4-2) ZnO nanostructures with different volumes of 25, 50 and 75 ml were deposited on glass substrates. From the characterization of the sample it was revealed that all laxyers have an n-type electrical conductivity, while the laxyer prepared at 50 ml has the highest electrical resistance and thus the lowest oxygen deficiency in the crystal lattice. Considering this fact we then in section 4-3 used the corresponding deposition condition to investigate the impact of Nitrogen as the impurity using Ammonium acetate (CH3COONH4) with Zn to N atomic ratio of 1:3. The data analysis showed that the electrical conductivity of this sample has changed to p-type. In the final step (section 4-4), the annealing process was acted on the pure and nitrogen doped samples at 500 ℃ in the presence of nitrogen flow (20 sccm) for 1h. It is found that in the doped sample, after annealing process the crystallinity of the laxyer has improved; also the mobility and hole carrier concentration has increased.