In this work, a titanium dioxide film was synthesized on a thin transparent polyester sheet by a reactive ion beam assisted deposition technique at room temperature. In this deposition process, a pure titanium target was sputtered by an argon ion beam under an oxygen atmosphere, and the growing film was concurrently bombarded by another argon ion beam in order to enhance both the adhesion of the film and the reactivity of the depositing titanium species with surrounding oxygen molecules. The microstructure of the as-deposited film was studied by Rutherford backscattering spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction analyses. The film was examined to be of rutile structure with a (110) preferential orientation. The optical properties of the film were measured by ultraviolet-visible transmittance spectroscopy and Fourier-transform infrared absorption spectroscopy experiments. It was found that the as-deposited titania film was quite transparent in visible region, while ultraviolet light could be filtered effectively, and infrared transmittance could also be reduced evidently. Our titania-coated polyester sheet should be applicable as a shielding cover on car windscreens or window glasses for the purpose of filtering ultraviolet radiation from the sunlight and partially insulating heat as well.