In this work various morphologies of tin dioxide nanostructures were synthesized via chemical reaction between tin chloride and different capping agents. The effect of different parameters such as precursors and temperature on the morphology of SnO 2 nanostructures was investigated. Photo-catalytic property of tin oxide was examined by degradation of methyl orange as organic pollutant in water under UV light irradiation. Nanostructures were characterized by X-ray diffraction, photo luminescence, Fourier transform infra-red, diffuse reflectance spectroscopy, scanning electron microscopy and transmission electron microscopy. For preparation of nanocomposite tin dioxide was added to poly carbonate and poly styrene and results show that the SnO 2 nanostructure can improve both thermal stability and flame retardant property of the polymeric matrixes. The enhancement is due to suitable dispersion and compatibility between polymeric chains and inorganic additive.