Tin oxide thin films have been investigated by X-ray Absorption Fine Structure spectroscopy (XAFS). XAFS provides a description of the structure of the films. The paper also presents a structural characterisation of the SnO2 thin films and their crystallisation behaviour by annealing at increasing temperatures. The x-ray absorption fine structure (XAFS) of Sn L-III edge in SnO and SnO2 have been investigated. The full multiple scattering approach has been applied to the calculation of Sn L-III edge XANES spectra of SnO. The calculations are based on different choices of one electron potentials according to Tin coordinations by using the real space multiple scattering method FEFF 8.2 code. The crystallographic and electronic structure of the SnO and SnO2 are tested at various temperature ranges from 300 to 873 K. We have found prominent changes in the XANES spectra of Tin oxide thin films by the change of the temperature. Such observed changes are explained by considering the structural, electronic and spectroscopic properties. The results are consistent with experimental spectra.