Heat capacities of aqueous solutions of sulfolane with 2-amino-2-methyl-1-propanol (AMP) were measured over the temperature range from 303.15 to 353.15 K with a differential scanning calorimeter. Twelve solutions of sulfolane + AMP + water that cover the mole fractions of water from 0.6 to 0.8 were studied. The liquid heat capacities of sulfolane alone and of binary mixtures such as sulfolane + water and sulfolane + AMP were also studied. The heat capacities of sulfolane and sulfolane + water were found to be in good agreement with those values reported in the literature. A Redlich-Kister type equation was applied to represent the composition dependence of the beat capacities of binary and ternary systems. For 132 data points of sulfolane + AMP + water, the fitted results of heat capacity calculations (overall average absolute percentage deviation (AAD%)) were 0.3 and 7.7% for the molar heat capacity and the excess molar heat capacity, respectively. The heat capacities of aqueous mixtures of sulfolane with AMP presented in this study can be used to estimate the head load of absorbents in acid gas capture process when using sulfolane + AMP + water as the absorbent. (C) 2007 Published by Elsevier Ltd on behalf of Taiwan Institute of Chemical Engineers.