The CdO and ZnO are n- type semiconductors are transparent conducting in nature, inexpensive, mechanically stable and highly resistance to oxidation. In the present work these films have been obtained from thermal annealing of chemically deposited CdS and ZnS thin films. The structural properties of chemically deposited CdS and ZnS thin films and thermally annealed CdO and ZnO thin films have been studied. From x-ray diffraction data it is observed that annealing of the thin films at a particular temperature enhance the structural properties.