PURPOSE: To produce the monodisperse metal oxide particles at a high slurry concn. by using an aq. alkaline soln. contg. water, of the specific molar number of the metal elements in an org. metallic compd. at the time of simultaneously dropping the aq. alkaline soln. different from the hydrolyzable org. metallic compd. into the aq. alkaline soln.

CONSTITUTION: The metal oxide particulates are produced at a high slurry concn. of ≥10wt.% by hydrolyzing the hydrolyzable org. metallic compd. in the aq. alkaline soln. The hydrolyzable org. metallic compd. such as alkoxysilane, and another aq. alkaline soln. which is properly selected by the kind of the org. metallic compd. are both independently, simultaneously and continuously dropped into the aq. alkaline soln. (I) before the water in the aq. alkaline soln. is consumed to run out at this time. The water in the aq. alkaline soln. is adjusted to 1 to 6 times mol per 1mol the metal elements in the org. metallic compd.