The log P value of pressurized CO2 at 50 degreesC was determined from the solubility of 1-octanol in CO2 and compared with other solvent parameters such as permittivity, epsilon, and polarity parameter, E-T(30). The log P indicated that pressurized CO2 is rather hydrophilic although it seems hydrophobic being judged from epsilon (r) and E-T(30). With a change in pressure from 3 to 11.8 MPa, the log P changed from 0.9 to 2.0 while epsilon (r) and E-T(30) changed only slightly. The log P was linearly correlated to the logarithm of the solubility of water among organic solvents. Pressurized CO2 was located close to the linear correlation line among the solvents at high pressure (>11 MPa) but its location deviated to the hydrophilic side with a decrease in pressure. Lipase-catalyzed esterification of stearic acid with ethanol and hydrolysis of ethyl stearate were carried out in pressurized CO2, benzene (log P = 2.0), and n-hexane (log P = 3.5). In spite of the lowest log P value for CO2, the reaction rate in CO2 was the highest among solvents tested in pressure range over 10 MPa. The reaction rate was strongly dependent on pressure of CO2. (C) 2001 Elsevier Science Inc. All rights reserved.