Hydrothermal treatment method was proposed to prepare boehmite and the effect of precursors on the morphology of beohmite was investigated. On the coordinate effect of organic and inorganic flower-like AlOOH assembled by nano-plates can be obtained by Al(NO3)3 as precursor. 3D urchin-like AlOOH superstructures consisting of nanoribbons were produced from hydrate AlCl3 as reagents. Dissolution and recrystallinity of intermediate product AlOCl caused this result. Globe and hollow sphere morphologies of beohmite were synthesized by Al2(SO4)3 in a water-alcohol system. The formation mechanism is also because of the dissolution and recrystallinity of intermediate product sodium sulfate aluminum. Beohmite prepared by hydrothermal treatment was transformed to γ- Al2O3 at 600°C. The morphologies of γ- Al2O3 powders were still kept their original forms.