TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Process: The sulfur-containing titanium oxide powder, dispersant and water medium or organic solvent are mixed, and subjected to wet pulverization processing, to obtain titanium oxide dispersion. A peroxo titanic acid-containing solution is mixed with the titanium oxide slurry after wet pulverization processing. The wet pulverization processing is performed by jet mill or beads mill. Preferred Composition: The concentration of sulfur-containing titanium oxide powder in the titanium oxide dispersion is 0.5-60 mass%. The additional amount of amine-type dispersant and/or carboxyl group-containing polymer dispersant is 0.2-20 mass% with respect to sulfur-containing titanium oxide powder. Preferred Properties: The titanium oxide dispersion has pH of 5-10. The ultraviolet visualization diffused-reflection spectrum of the sulfur-containing titanium oxide powder in the dispersion is measured. The integral value of light absorbency at a wavelength of 300-350 nm, 350-400 nm and 400-500 nm is 1, 0.3-0.9 and 0.3-0.9, respectively.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Dispersant: The dispersant is amine-type dispersant and/or carboxyl group-containing polymer dispersant, preferably peroxo titanic acid or its salt. The amine-type dispersant is amine salt(s) of alkylamine and polycarboxylic acid. The carboxyl group-containing polymer dispersant is polycarboxylic acid or its salt. The organic solvent is alcohol. EXAMPLE - A pale yellow color sulfur-containing titanium oxide powder having sulfur content of 0.25 mass% and specific surface area of 180 m2/g, was prepared using titanium tetrachloride aqueous solution, aqueous ammonia, pure water and thiourea. The sulfur-containing titanium oxide powder was added to pure water with ammonium polyacrylate as dispersant, and stirred. Preliminary pulverization processing of the resulting mixture was carried out using a ball mill disintegrator, at normal temperature for 8 hours, to obtain sulfur-containing titanium oxide slurry. The slurry had sulfur-containing titanium oxide concentration of 20 mass%. Ammonium polyacrylate was added in an amount of 5 mass% with respect to sulfur-containing titanium oxide dispersion amount. Pulverization processing of the obtained slurry was carried out using wet jet mill at normal temperature for 5 times. 0.85 mass% peroxo titanium oxide aqueous solution was added to the resulting slurry, and stirred to obtain titanium oxide dispersion having titanium oxide powder concentration of 10 mass%. The dispersion had particle size distribution of 17 nm, D10 diameter of 0.09 nm, D50 diameter of 0.11 nm and D90 diameter of 0.12 nm, and had excellent photocatalytic activity.