Precursor of nanosized TiO2 was prepared by alkoxide hydrolysis method. It was dried by common drying, far infrared drying, vacuum drying and supercritical drying before heat-treated at 600°C and 800°C. Influence of drying process and treatment temperature on the crystalline phase composition and photocatalytic activity were analyzed. The photocatalytic activity of the TiO2 dried by common and far infrared drying is higher than that of the TiO2 dried by vacuum and supercritical drying after treated at 600°C. The photocatalytic activity of the TiO2 dried by common and far infrared drying is lower than that of the TiO2 treated by the other two drying methods after treated at 800°C.