Selective deposition was observed in the growth of silicon dioxide using liquid-phase deposition process. By adjusting the growth parameters, the key mechanism leading to the observed selective deposition was identified. It is found that within the same period of time, a thicker oxide film is grown when the native oxide on the silicon substrate surface is not removed. This difference in oxide growth is attributed to different surface conditions which affect the initial growth rather than the subsequent deposition rate. It is proposed that the chemical reaction that replaces Si-H surface bonds to Si-OH bonds as well as the formation of some kinds of intermediate product are the rate limiting processes for initial growth. On the other hand, changing the supersaturation level of the hydrofluosilicic acid results in different deposition rates although the substrate surfaces are the same. Combining these results, a critical concentration of hydrofluoric acid which depends on the substrate surface conditions is determined. As long as the concentration of hydrofluoric acid in the solution is smaller than this critical value, the oxide deposition occurs. Otherwise, no oxide can be grown.