Abstarct: In this experimental research work we have studied the morphological, structural and optical properties of pure ZnO nanostructures grown on glass, ITO and Si (100) substrates by spray pyrolysis and thermal evaporation methods. In this study we have used the Field Emission Scanning Electron Microscopy (FESEM), X-ray diffractometer (XRD), UV-Vis-NIR spectrophotometer and Photoluminescence (PL) apparatus. In samples grown by spray pyrolysis method by using a 0.1 M zinc chloride solution at different substrate temperatures (400-550 °C) we found: the as-grown laxyers have a nanostructure feature with a polycrystalline wurtzite structure and preferential (002) orientation. Optical data analyses show that as the substrate temperature increases the optical transmission coefficient, the film thicknesses and the band gap of the material decreases. In samples grown by thermal evaporation technique ZnO nanostructures were synthesized by the pure (99.9%) mextallic zinc powder in the presence of oxygen as the reaction gas. The effects of the influence of boat temperature, the distance of the substrate from the boat and the substrate material (Si, ITO) on the physical properties of the grown laxyers were investigated. We found all samples have a polycrystalline phase with wurtzite structure and the surface of the samples are covered with various types of nanostructures including nanorods, nanowires, microcages, flower-like, and multipod nanostructures.