In this study, Indium Tin Oxide (ITO) thin films were deposited by electron beam evaporation on white glass substrates with thicknesses of about 50, 100 and 170 nm. We investigated structural properties by X-ray Diffraction (XRD) and X-ray reflectivity (XRR). The results showed that ITO thin films have a crystalline structure with a domain that increases in size with increasing thickness. For uniform electron density, as the thin film roughness increases, reflectivity curve slope also increases. Also thinner film has more fringes than thicker film. The roughness determines how quickly the reflected signal decays. XRR technique is more suitable for very thin films, approximately 20 nm and less.