In this paper, we report the density of a solvent system containing propylene glycol (PG)+2-amino-2-methyl-1-propanol (AMP)+water at 303.13, 308.15, and 313.15 K and different PG mole fractions ranging 0.02 to 0.60. The data fit in the Redlich-Kister equation for excess molar volume. We also report a new set of physical solubility data for CO2 in PG+AMP+H2O, estimated from N2O solubility (at the same range of molar compositions and temperatures) by way of the so-called N2O analogy, a method which has been used and proven to give reliable estimate of CO2 solubility in previous studies. The measured solubility data for N2O in the solvent system made a good fit with the differential Henry's law coefficient model.