In this paper, Nano-TiO2 was prepared by sol-gel method, and then the wet gel particles that produced by this method were dried by infrared drying (IFD) and supercritical fluid drying (SCFD) technology respectively. After that,the properties of the samples were elaborated by XRD,SEM and BET,meanwhile the photocatalytic oxidization degradation activity of the samples to Sudan red Ⅰ was also inspected. The test results show that the samples prepared by IFD are the mixed crystal of anatase and rutile with diameter range of 10 -30 nm. Compared...