Titania prepared by the calcination of sludge from waste water coagulated by titanium chloride was used as a substituent of the reinforcing material for silica-filled SBR compounds. The titania, mainly composed of anatase, was loosely aggregated and treated with various alkoxy silanes. The partial substitution of silica by the titania and silanemodified titania usually accelerated the cure rate and enhanced the thermal stability of the silica-filled SBR compounds. The extremely low concentration of hydroxyl groups of titania lowered the silica-silica interaction by introducing titania into the moieties of silica particles, resulting in decreases of the Payne effect and fractional hysteresis. Although the titanias modified with silanes were generally effective in enhancing the tensile and dynamic properties of the silicafilled SBR compounds, the silanes which contained mercapto groups, enabling them to react with rubber molecules, exhibited a high wet traction and low rolling resistance without sacrificing their tensile properties.