High performance TiO2/polymer nanocomposites with enhanced thermal and excellent UV-shielding properties have been successfully prepared by means of the anatase TiO2nanoparticles homogeneously dispersed in the poly (methyl methacrylate/butyl acrylate/methacrylic acid) [P (MMA/BA/MAA)] matrix via a miniemulsion polymerization process. Highly crystalline TiO2 nanoparticles with 5–8 nm diameter, were synthesized by a non-aqueous process and then modified with γ-Methacryloxypropyltrimethoxysilane (A174) to improve the compatibility with polymer. FTIR, TGA and dispersity tests in monomers/water verify that the A174 is chemically bonded onto the surface of TiO2nanoparticles. TEM, SEM and EDS analyses indicate that the TiO2 nanoparticles are homogeneously dispersed in the polymer matrix. TGA and DSC studies confirm that the thermal properties of the resultant nanocomposites are significantly enhanced with respect to the neat polymer. UV–vis transmission spectra results reveal that the films with TiO2 nanoparticles has an excellent UV-shielding property, even at 1.5 wt% TiO2nanoparticles loading can almost block the UV light below 350 nm while still having a high visible transparency. Therefore, the resultant nanocomposite films could be used as transparent UV-shielding materials.