Surface-modified titanium dioxide particles which have a surface
chemically modified with a hydrophilic polymer, wherein a carboxyl group
of the hydrophilic polymer and titanium dioxide are bound through an
ester bonding; and a method for producing the surface-modified titanium
dioxide fine particles, which comprises mixing a dispersion comprising
titanium dioxide fine particles having a particle size of 2 to 200 nm and
a solution of a water-soluble polymer, heating the resultant mixture to a
temperature of 80 to 220.degree. C., to thereby bind both the components
through an ester bonding, and removing an unbound water-soluble polymer,
to purify the resuultant particles. The surface-modified titanium dioxide
fine particles exhibit excellent dispersibility and stability in an
aqueous solvent over a wide pH region including a neutral range.