ZnO thin film were deposited by spray pyrolysis on glass substrates, using zinc nitrate as precursor with different molar concentrations varying from 0.05M to 0.2 M. To study the structural proprieties of the film , the different technique was used as the X-ray diffraction, atomic force microscopy (AFM), Raman scattering , and FTIR . The optical properties were explored by transmission, reflectivity and Photoluminescence techniques. The ZnO thin films obtained in this paper are polycrystallines, the grain size increases when the molar concentration of Zn precursor was increasing. The films are transparent in visible region, this transmission values decreases when the molar concentration increase caused by the increasing of surface roughness