Abstract Propane (R290) is considered as a promising substitute for R22 or R410A used in room air conditioners. In this work, the solubility of R290 in two mineral oils (3GS and 4GS) was measured at the temperatures from 253.15 K to 343.15 K using isochoric saturation method. The non-random two liquid activity coefficients model was used to correlate the experimental solubility data. The absolute average relative deviation of equilibrium pressure between experimental data and calculated values from the model was 1.93% and 1.79% for R290/3GS and R290/4GS system, respectively. In addition, the enthalpy of the refrigerant and lubricating oil mixtures was calculated, and the relationship of the pressure-enthalpy-quality (p-h-X diagrams) of the mixtures was given and analyzed at the oil circulating mass fraction of 2% and 4%, respectively.