A thin layer of nano TiO2 was deposited on PET fiber using tetrabutyl titanate by hydrothermal processing. The TiO2-loaded fiber was characterized by scanning electron microscope (SEM)‚ X-ray diffraction (XRD)‚ Fourier transform infrared spectroscopy (FT-IR)‚ X-ray photoelectron spectroscopy (XPS)‚ differential scanning calorimetry (DSC) and thermal gravimetric (TG) analysis. PET fabrics before and after treatments were also examined for the reflectance spectrum, tensile properties and water absorption. The results showed that pure anatase TiO2 crystallite could be synthesized from tetrabutyl titanate aqueous solution. The thin film constituted by nano TiO2 particles was grafted onto the fiber surface by chemical reaction. The onset decomposition temperature decreased but the endothermal and exothermal temperatures increased. As compared with the untreated fabric, the water absorbency of the TiO2-loaded fabric was slightly improved. Owning to the shrinkage of fabric size‚ the breaking load and tensile strain in warp and weft directions increased to some extent.