The synthesis of organized mesoporous alumina has exploring new territory for application of this type of materials, particularly as catalysts or catalyst supports. High specific surface area and thermal stability are the major requirements for alumina as catalyst supports. In this paper, we report a facile synthesis of ordered and high thermal stability mesoporous alumina doping with La or Ce ions under hydrochloric acid conditions. Thermal stability improvements by rare earth (La and Ce) doping are discussed. In our work, we find that both rare earth doping can effectively stabilize the amorphous walls of alumina mesostructures. This material presents the ability to maintain the surface area and pore structure upon prolonged heating below 700 ℃. Further more, as the results shows the modification of La for improving the thermal stability is more effective than Ce. Besides, Cl- does not strongly influence the self-assembly process in the closed system.