Surface tensions of carbonated 2-amino-2-methyl-1-propanol (AMP) and piperazine (PZ) aqueous solutions were measured by a surface tension meter which employs the Wilhemy plate principle. A thermodynamic model was proposed to correlate the surface tensions of both CO2-unloaded and CO2-loaded aqueous solutions by introducing the contribution of CO2 loading into the formulation of surface tension. Based on experiments and calculations, the effects of temperature, mass fractions of amines, and CO2 loading on surface tensions of carbonated aqueous solutions were demonstrated.