NThe nanosized porous TiO₂ powders were synthesized by using the titanium sulfate solution through a simple sol-gel route, where the formamide was used as the pH adjusting agent. The X-ray diffraction, the scanning electron microscopy, the transmission electron microscopy and the N₂ Adsorption/Desorption were used to analyze the prepared samples. The results show that the prepared TiO₂ powders have a high thermal stability and maintain as a monophasic anatase in cases of calcination from 450℃ to 750℃, furthermore, the main crystalline phase remains as that of anatase even at 850℃. The crystalline grains of TiO₂ powders grow larger and the specific surface area is reduced with enhancing the calcination temperature. The microstructure of TiO₂ powders is that of aggregation of nanocrystalline with diameter of approximately 10 nm in case of calcination at 550℃. The specific surface area of the prepared samples is approximately 219.70m²·g^-1 after calcinating at 550℃ and there is a specific bimodal pore structure in the prepared samples.