Reliable experimental data for solubility and enthalpy of solution of acid gases in aqueous solutions of alkanolamines are required for the design of gas treating equipments and to develop thermodynamic models describing this process. A customized flow mixing unit adapted to the SETARAM C-80 calorimeter [1] was used to measure the enthalpy of solution of CO2 in aqueous solutions of alkanolamines (MEA, DEA, TEA, AMP and MDEA). The influence of pressure, temperature and amine composition was studied. The equilibrium constant were also determined for the five amines considered in the temperature range between 298 K and 333 K by potentiometric method.