<p>Disclosed are rutile titanium oxide ultrafine particles obtained by maintaining the pH of an aqueous solution of a titanium compound having a Ti content concentration of 0.07-5 mol/L within the range from -1 to 3 in the presence of a chelating agent. Such rutile titanium oxide ultrafine particles are useful for optical catalysts, high refractive index material, ultraviolet absorbing material and the like.</p>
