An analysis is made of the characteristics and mechanisms of extraction with propane of heavy oils from the porous medium of the Jiang 37 Block, Daqing Oilfield (China), which is characterized by shallow depth of oil occurrence, a thin oil-bearing stratum, poor permeability, and high oil viscosity. The results show that propane has a strong heavy oil extraction capacity and that the solubility of propane in the oil and density and viscosity of the oil depend on pressure. It is shown by gas chromatography and IR spectroscopy that the composition of the oil changes during the propane extraction process: the content of light components increases and the content of heavy components decreases due to deasphalting.