The present invention relates to fine particles of a tin-modified rutile-type titanium dioxide obtained through the reaction of an aqueous solution of a titanium compound having a Ti concentration of 0.07 to 5 mol/l at a pH in the range of -1 to 3 in the co-presence of a tin compound at a molar ratio of tin to titanium (Sn/Ti) of 0.001 to 2, wherein said fine particle has an Sn/Ti composition molar ratio of 0.001 to 0.5, and a short axis and a long axis of a crystal grain diameter thereof have a length of 2 to 20 nm.