In this work, the CO2 solubility predicted for amines of DEA and MDEA by using the O'Connell (1964) expression as a base model. This expression fits between the solvent compositions and the thermodynamic properties beside the gas solubility. The solvent activity coefficient, Gibbs energy and Henry's law constants have been generated using Aspen plus data analysis tools. The self-interaction binary parameters (Margules parameters) have been calculated based on Henry constant's values. The data input for this work depends on the amine system process conditions (temperature range between 298.15 K and 393.15 K), material's composition (concentrations of 10 wt, 20 w and 30 wt ). For both of the DEA and MDAE and the pressure fixed to be 101.3 KPa. The solubility values of this work give satisfactory results compared to the literature data. © (2014) Trans Tech Publications, Switzerland.