Thermal decomposition characteristic of calcium magnesium acetate (CMA), calcium acetate (CA) and magnesium acetate (MA) are investigated through thermogravimetric (TG) analysis at the heating rates of 5K min(-1), 7.5 K min(-1), 10 K min(-1) and 15K min(-1). After dehydration, the evaporation of carboxylic radical and carbon dioxide of CMA and CA exist in two separate segments, but for MA, this occurs together in just one segment without clear borderline. The curves of calculated CMA (C-CMA) and the deduced characteristic parameters illustrate the different characteristic of CA and MA from the corresponding components in CMA which may be the reason for the different performances of these sorbents in SO(2) and NO(x) reduction. Also, the kinetic parameters of activation energy and reaction order of the three sorbents are calculated through Vyazovkin method and Avrami theory, respectively. (C) 2010 Elsevier Ltd. All rights reserved.