Tin Oxide nanoparticles (SnO2-NPs) were prepared by mixing (SnCl4.5H2O) with distilled water at room temperature. The samples were characterized for their crystalline structure, morphology and chemical structure by using X-ray diffraction (XRD), Rietveld refinement, scanning electron microscopy (SEM) and fourier transform infrared spectroscopy (FTIR). The XRD data and Dicvol 91 software analysis the crystal system was found to be tetragonal structure for samples prepared under stirring time for (24,48,72) h with (a=4.745 , c=3.184), (a=4.768 , c=3.255) and (a=4.776 and c=3.257) respectively. The average of crystallite size calculated by using SEM it was 9.45 nm, 14.7 nm and 21.5 nm, for the same times, previously mentioned of stirring. The effect of stirring time on the crystal lattice distortion ratio, specific surface area and dislocation density was discussed. The optical band gap values of SnO2-NPs were calculated to be about 3.4eV, 3.37eV and 3.2eV under stirring time for 24 h, 48 h and 72 h respectively by optical absorption measurement.