Abstract: Pseudoboehmites with a variety of morphologies were prepared via hydrothermal method using activated alumina as main material directly or with the hydrolysis product of aluminum salt as seed crystal.The morphology，phase structure，and pore structure were characterized by scanning electron microscopy，X-ray diffraction，and physical adsorption.It was shown that the activated alumina was plastic，and can form pseudoboehmite with different morphologies，such as prismatic shape，pompon，and flake.A new method was provided for preparation of controllable morphology of pseudoboehmite.

Key words: pseudoboehmite, activated alumina, inorganic aluminum salt, hydrothermal method