Effects of temperature and pressure on supercritical CO2-water extraction of vanillin from its aqueous solution were investigated using a fast and continuous extraction and separation apparatus developed recently. Experiments were conducted under the temperature of 40-60 degrees C and the pressure of 10.0-24.4 MPa. The partition coefficient of vanillin to supercritical CO2-rich phase decreased with increasing temperature at fixed pressures, while it increased with increasing pressure at fixed temperatures. The analysis by van't Hoff plot suggests that the values of enthalpy and entropy change in the process of mass transfer from water to supercritical CO2 under conditions investigated are constant and negative. This suggests that the partition process is enthalpy driven process, which is same as the mass transfer from water to 1-octanol. The natural logarithm of partition coefficients increased linearly with the natural logarithm of CO2 density at fixed temperatures. Since the natural logarithm of solubilities also increases linearly with the natural logarithm of CO2 density, the behavior of partition coefficient is considered to reflect the variation of vanillin solubility in supercritical CO2, which is also same as the partition process from water to 1-octanol. (C) 2018 Elsevier B.V. All rights reserved.