Abstract: In this study, cadmium oxide thin films have been prepared onto glass substrate using SILAR method. The films were prepared at 85°C then annealed at 300°, 350° and 400°C for 1 h. The results of XRD reveal that all films have a polycrystalline structure with cubic phase. The UV-visible spectrophotometer analysis revealed that the value of energy band gap decreased with increase in annealing temperature from 2.24, 2-1.9 eV at 300°, 350° and 400°C.