Abstract: Preparation of pseudo-boehmite by hydrothermal homogeneous precipitation was carried out in aluminum sulfate-urea aqueous solution. The effect of hydrothermal reaction temperature and time on the morphology, structure, specific surface area, pore volume and average pore size of the prepared samples were characterized and compared by SEM, XRD and N2 physical adsorption. Test results showed that when the reaction temperature was increased from 100℃ to 140℃, the particle morphology of the prepared pseudo-boehmite changed from sphere to fiber, its specific surface area increased from 15.7 m2/g to 190 m2/g, pore volume increased from 0.02 mL/g to 0.36 mL/g, average pore size increased from 4.6 nm to 8.3 nm. XRD patterns indicated that all the samples prepared with mixed solutions of n(Al3+): n(urea)=1:2, reacting under 100—160℃ for 12 h, were pseudo-boehmite with relatively high crystallinity; in which sample prepared at 140℃ for 16 h exhibited improved properties, such as having specific surface area of 201 m2/g, pore volume of 0.44 mL/g, average pore size of 8.7 nm and concentrated pore size distributions.