TiO₂-coated SiO₂ fine particles were synthesized by the hydrolysis of TEOS and TEOT in order to investigate the growth mechanism of TiO₂ particles coated on monodispersed silica seed particles using the semi-batch reactor. Firstly, SiO₂ seed particles with narrow particle size distribution were prepared by controlled hydrolysis of TEOS solutions. Secondly, SiO₂ seed particles were allowed to coat and grow by further addition of TEOT as a precursor of TiO₂ particles. Nielsens chronomal analysis and Overbeeks theory were applied to clarify the growth mechanism of TiO₂ particles coated on silica seed particles. As a resultz, it was found that the particle grouth mechanism was presumed to be a surface reaction in which the rate determining step was a first-order polynuclear-layer growth mechanism and the growth rate constant, ^k_p was about 2.95 x 10^-6 cm/sec.