Absorption of a series of low molecular weight solutes into polyurethane was investigated in supercritical carbon dioxide with different conditions. The effect on the amount of solutes absorbed in polyurethane due to these factors such as pressure, temperature, absorption time, decompression time, the character of solutes, and the amount of cosolvent was examined by a gravimetric method. The absorption mechanism was discussed. The desorption of solutes in polyurethane showed a dependence on the logarithm of time.