The process parameters of the formation colloidal silica via sodium silicate has been investigated in this paper. Sodium ion of sodium silicate was removed by ion exchanging to obtains he active silicic acid which was titrated to the solution of potassium hydroxide (KOH) to form the colloidal silica. In the study, results showed the mean particle size of colloidal silica was influenced by the KOH concentration, formation temperature and titration rate of active silicic acid. High KOH concentration, high formation temperature and low titration rate of active silicic acid would help the particle growth to form the larger particle size of colloidal silica. Unfortunately, the colloidal silica formed at these conditions were unstable.