In order to obtain CO2-absorbents to eliminate CO2 concentration locally, Bi2O3-La2O3 mixed powders were prepared by mechanical alloying (MA) method using a planetary ball-milling machine. CO2-absorption and desorption properties were checked by TG-DTA for the obtained powder samples. As a result, the sample shown by (Bi2O3)(1-x)(La2O3)(x) [x less than or equal to 0.50] was found to form alpha-Bi2O3-solid solution with repeated CO2-adsorption and desorption around 400-500 degreesC. Absorbed and desorbed CO2 contents varied with MA time: the 72 h MA'ed sample had a larger CO2 content than the 24 h MA'ed sample. The performance depended on the sample composition, and (Bi2O3)(0.70)(La2O3)(0.30) was found to have the highest performance in the present system. (C) 2004 Elsevier Ltd. All rights reserved.