We have investigated effects of the reaction conditions such as mixing of solution, reactant concentration, feeding time and molecular weight of alcohol solvents on the size and mor- phology of silicon oxide in a sol-gel process in Rushton type reactor. To describe the intensity of mixing of solution the power input, which means the energy dissipated in the solution, was used. The particle nucleation and growth processes of silicon oxide were varied with all the reaction conditions. However, the particle morphology of silicon oxide depended mostly on the reactant concentration and molecular weight of alcohol solvents under various reaction conditions. If the supersaturation level of silicon oxide in the solution was promoted by variation of reaction conditions, the particle nucleation and growth processes were facilitated and it resulted in reduction of relative induction time and in increase of mean particle size of silicon oxide. To explain the principal mechanism of particle growth process of silicon oxide the two-step growth model was applied.