The thermal stabilization mechanism of barium and the effects of preparation methods, barium content and calcination temperature were studied by BET specific surface area and powder X ray diffraction. It was found that barium can stabilize the alumina at high temperature (1000 ℃) and the stabilization effect was enhanced with the increase of the barium content, whereas, the overabundance weakened the stabilization effect. The preparation methods influenced the thermal stability of alumina and the stabilization effect of barium. At high temperature, the stabilization effect of barium species can be attributed to the dispersed baria and not hexaaluminate retarding the loss of specific surface area due to the sintering and αphase transformation within the initial 1 h of the calcination process. The thermal stabilization mechanism of barium and the effects of preparation methods, barium content and calcination temperature were studied by BET specific surface area and powder X ray diffraction. It was found that barium can stabilize the alumina at high temperature (1000 ° C) and the stabilization effect was enhanced with the increase of the barium content, but the overabundance weakened the barium content, while the overabundance weakened the barium content, but the overabundance weakened the barium content to the dispersed baria and not hexalum retard retarding the loss of specific surface area due to the sintering and alphaphase transformation within the initial 1 h of the calcination process.