Nearly monodisperse spherical silica particles, 200~300 nm in diameter, were produced via a dry route for the first time through a two-stage hydrolysis of SiCl4 vapor. In the first stage, the SiCl4 was partially hydrolyzed in a batch reactor at 150 ℃ to form nearly monodisperse silicon oxychloride particles. In the second stage, the oxychlorides were hydrolyzed further in a tubular reactor to have produced silica with the morphology and size nearly conserved.