Sulfation of the alkali-salt-promoted CuO/γ-Al 2 O 3 sorbent has been carried out in a thermogravimetric analyzer, and the thermal decomposition characteristics of the sorbent and alkali salt in N 2 gas were determined by a differential thermal analyzer. An addition of alkali salt to the sorbent increases SO 2 sorption and reduces the temperature range for bulk sulfation of the CuO/γ-Al 2 O 3 sorbent. The main product in sulfation of the LiCl-promoted sorbent above 450 °C is found to be Al 2 (SO 4 ) 3 by an X-ray diffractometer. The rank for sulfur removal capacity of alkali salts as additives in CuO/γ-Al 2 O 3 sorbent is found to be LiCl > LiBr ≈ NaCl > LiF ≈ KCl ≈ NaF. In the cycle test of sulfation-regeneration at 500 °C, SO 2 removal capacities of LiCland NaCl-promoted sorbents are over 3 times than those of the promoter-free sorbent for up to 30 cycles.