Abstarct: In this thesis, the physical, thermochromic and electrochromic properties of VO2 and V2O5 thin films were investigated. In this research, for samples characterizations has been used of field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Raman spectroscopy and ultraviolet-visible-near-infrared optical spectroscopy (UV-Vis-NIR) at room temperature and 90˚C for thermochromic properties. In chapter 4, vanadium oxide thin films were synthesized by thermal oxidation method. The films were investigated by changing some parameters such as oxidation temperature, different gas flux ratios (CO2-N2), laxyer thicknesses and doping with Mo. The results obtained for thermochromic application showed that the sample with thickness of 100nm at 450˚C oxidation temperature with flux of CO2-N2:50-50 sccm has the lowest critical temperature of 31˚C with significant values of Tlum-av and ΔTsol. In the next part, VO2 thin films were synthesized by magnetic sputtering for thermochromic application and were studied the effect of different parameters, including thicknesses and different fluxes of Ar/O2 gases. The results showed that the sample with thickness of 150nm and flux of Ar/O2:7/1 has the lowest critical temperature of 44˚C. In chapter 5, V2O5 thin films were synthesized by sputtering for electrochromic application on FTO substrate and were investigated the effect of different parameters of Ar/O2 gases. The results in this section showed that the sample with gas flux of Ar/O2:25/1 has the best color efficiency. In the next, V2O5 samples were synthesized on FTO substrate by spray pyrolysis method for electrochromic application on FTO substrate and were studied different parameters such as spray solution concentration, annealing in different environments, doping with WO3 with different percentages and annealed at 400˚C has the best color efficiency of 40cm2/C.