In this work, the temperature influence and blending effect on the partition of methyl methacrylate between poly(methyl methacrylate) and compressed gaseous carbon dioxide were investigated; the cosolvent effect of ethanol on the partition of acetone between poly(carbonate biphenol A) and compressed gaseous carbon dioxide was also studied by using an in situ IR. spectroscopy method at fluid pressure lower than 7.0 MPa. The temperature increase and the cosolvent addition decreased the partition coefficient of solute between polymer and compressed gaseous carbon dioxide. Interestingly the blending of the polymers increased the partition coefficient, and the distribution of methyl methacrylate between the poly(methyl methacrylate)/poly(vinylidene fluoride) complex and compressed gaseous CO2 was not a simple additive of the distribution of the two separate at a pressure lower than 6.0 MPa.