An anatase-type ultrafine particulate titanium oxide produced through a vapor-phase process, which has low chlorine content and exhibits excellent dispersibility as compared with conventional titanium oxide having a BET specific surface area comparable to that of the ultrafine particulate titanium oxide. When the ultrafine particulate titanium oxide is subjected to dechlorination, the titanium oxide satisfies the relation between BET surface area (B) and chlorine content (C) represented by the formula C.ltoreq.650e.sup.0.02B. The ultrafine particulate titanium oxide has a D90 of 2.5 (m or less as measured by means of laser diffraction particle size analysis. The present invention also provides a process for producing the ultrafine particulate titanium oxide.