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A series of titanium dioxide (TiO 2 thin films were grown onto soda-lime glass substrates, using radio frequency (rf) magnetron sputtering at room temperature, with a TiO 2 ceramic target, argon was the plasma gas and oxygen was the reactive gas. The experimental studies used different rf power, sputtering pressures, O 2 /(Ar + O 2 , flow rate ratios and deposition times. This paper examines the optimization of the sputtering parameters for TiO 2 thin films, using the Grey-Taguchi method. In the confirmation runs, Grey relational analysis shows that improvements of 9.83% in the deposition rate, 5.76% in the photoinduced decomposition of methylene blue and 6.49% in the photoinduced hydrophilicity were noted. The results of X-ray diffraction (XRD) showed that the films had anatase phase. The structure and morphology of deposited layers were evaluated by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The TiO 2 thin films were annealed in a vacuum ambient (6.0 × 10 −4 Pa), at temperatures of 200, 250, 300, 350, 400 and 450 C, for a period of 40 min. The surface grain size and roughness of TiO 2 thin films after annealing were around 38.86∼59.45 nm and 2.97∼3.31 nm, respectively. Both the optimization of the sputtering parameters and thermal annealing are the key factors for the TiO 2 films to yield fast-response excellent photoinduced hydrophilicity with the contact angle decreased to less than 5 , after UV irradiation for 12 min.