Functionalized TiO2 nanoparticle containing isocyanate groups can extend the TiO2 nanoparticle chemistry, and may promote their many potential applications such as in polymer composites and coatings. This paper describes a facile method to prepare functionalized TiO2 nanoparticle with highly reactive isocyanate groups on its surface, via the reaction between toluene-2, 4-diisocyanate (TDI) and hydroxyl on TiO2 nanoparticle surface. The main effect factors on the reaction of TiO2 with TDI were studied by determining the reaction extent of hydroxyl groups on TiO2 surface. Fourier-transformed infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) confirmed that reactive isocyanate groups were covalently attached to the TiO2 nanoparticle surface. The dispersion of the TDI-functionalized TiO2 nanoparticle was studied by transmission electron microscopy (TEM). Owing to the TDI molecules covalently bonded on TiO2 nanoparticle surface, it was established that the TiO2 nanoparticle can be uniformly dispersed in toluene, thus indicating that this functionalization method can prevent TiO2 nanoparticle from agglomerating. (C) 2012 Elsevier B.V. All rights reserved.