Abstarct: In this thesis pure and Boron doped SnO2 nanoparticles were synthesized by Sol-Gel method. Sturactural and optical properties of this nanostructures were investigated by X-Ray diffractometer, UV-Vis spectrometer, Field emmision scaninig electron microscope (FESEM) and Fourier transform inferared (FTIR) spectroscopy. The results of the X-Ray diffraction were showed that the samples are polycrystalline with a rutile structure. The crystallite size of the sample was decreased with as the doping concentration increased. Moreover increased it was as annealing temperature and calcination time decreased. The plan view FESEM images were demonstrated that the synthesized samples are nanosized. The band gap of the samples was determined using the reflection spectrum. The results were showed as the crystallite size, increases the band gap also increases. Absorbtance peaks in the FTIR spectra were justified the formation of SnO2 crystallines.