To study the effect of Nd:YAG laser on the properties of structural and optical values of the energy gap of cadmium oxide (CdO) films, have been prepared using chemical spray pyrolysis and deposited on a glass substrate for concentrations(0.05, 0.1, 0.15)M at temperature (350°C) ,using 6 spray rate during (10) second for each spray . To study the optical properties of the film Prepared (CdO) before and after irradiation Nd:YAG laser with energy (200) mJ at different times (5,10,15)sec and at (1) meter far from the source using a(UV-Visible) spectrometer device and the extent of wavelengths, (300-1100) nm the results showed that the energy gap increased with increasing concentrations and was the ideal value when the concentration of (0.1)M, where the value of energy gap is (2.25)eV, but after laser irradiation redueced to (2)eV. The Atomic Force Microscope(AFM) has been used to study the structural properties of the composition and topography of the surface in two and three dimensions of the films prepared before and after irradiation, the results indicate that the surface rate roughness and the average root of the square less after irradiation, and it is observed ideal value for this property is at a concentration of (0.1)M. The crystalline structures and surface morphology of CdO thin film examined by XRD analysis. The result showed the films are polycrystalline for and crystalline granules prevailing levels of growth are at (220), (200), (111) the irradiation led to a slight change in the angle of diffraction in the lattice constants (a) and a decline in giving the peak tops.