As a functional inorganic material, LiAlO2 was focused on widely, especially in the field of tritium breeder of fusion reactor. In this article, the proper reaction conditions and mechanism to synthesis the γ LiAlO2 by solid state method are considered. In the experiments, it has been found that the phase of β and γ LiAlO2 are only produced by the reaction of LiOH and Al2O3, while the α and γ LiAlO2 can be obtained by the reaction of Li2CO3 and Al2O3. As compared with Li2CO3 and Al2O3 reacted at 900～1000℃ for the preparation of γ LiAlO2, the γ LiAlO2 can also be made by the reaction of LiOH and Al2O3 at some more lower temperatures that is due to the bulk diffuse mechanism. But the former can get better crystal and have smaller particles for the mechanism of surface fast reaction. As a result, the sub micron γ LiAlO2 powders with the diameter less than 0.3μm are obtained.
