This paper deals with the effect of CO 2 laser irradiation on the optical properties of cadmium oxide (CdO) films prepared by chemical spray pyrolysis (CPS) technique. The films deposited on glass substrate using such as an ideal value concentration of (0.1) M Cd(NO3)2.4H2O at temperature (350°C) ,using 6 spray rate during (10) second for each spray .Transmittance ,absorption, absorption coefficient, optical constants, optical energy gap were recorded in order to estimate these films. The obtained films were exposed to CO 2 continuous laser with energy (2) Watt at interval time (15) sec at (1) meter far from the source, extend of wavelength nm .Results of the (CdO) films reported after irradiation showed on improvement of optical energy gap which is shifted from (2.25) eV to (2.09) eV.