The chlorination characteristics of CaO-MgO-based compounds from calcined dolomite were experimentally studied in the temperature range of 473 to 1,073 K and compared with those of CaO and MgO. Experimental results showed that the conversion of CaO for chlorination had a maximum value at MgO/CaO molar ratio of 0.74. The maximum HCl sorption capacity per unit weight of calcined dolomite was 1 to 1.3 times as large as that of calcined calcite.