Abstarct: In this thesis, the synthesis and investigation of structural and optical properties of TiO2-SnO2 core-shell have been studied. The samples were synthesis by core-shell method. To characterize optic properties of the samples, UV-Vis spectroscopy in the range of 300 to 1100 nm wavelengths and also photoluminescence spectroscopy were used. To investigate the structural properties. the X-ray diffraction (XRD) Technique and to study the surface morphology of the samples a field emission electron microscope and a transmittion electron microscope (TEM) were used. Core-shell samples of TiO2-SnO2 with three different ratios of shell to core 5:0.5, 5:0.67, and 5:1 were prepared. Investigation of the X-ray diffraction spectra for SnO2 samples without and with annealing at 350 °C and 450 °C showed that all have casterite tetragonal structure. The X-ray diffraction spectra of TiO2 and annealed sample at 350 °C showed that the sample without annealing has an amorphous structure and the annealed sample has an anatase phase tetragonal structure. Investigation of the x-ray diffraction spectra for core-shell samples indicated the core-sell phase is formed and the diffraction peaks of both of them are present in the diffraction spectra. FESEM images for tin oxide (SnO2) and titanium oxide (TiO2) samples indicate grains stick together and for the core-shell samples represent almost spherical and homogeneous grains. Optical investigation of the samples showed that the band gap of the core-shell samples was indirect, like the TiO2 core itself, and decreases by increasing the ratio of shell to core.