A new model for describing two - phase flow in a supercritical fluid extraction packed column was derived whereThe model was tested by measuring the experimental data for two - phase flow characteristics in a supercritical fluid extraction packed column of 25mm in diameter with structured packings and θ metal rings for the systems of carbon dioxide-isopropanol-water and carbon dioxide - ethanol -water under pressures from 8 to 15MPa and at 35 C. It showed that the model for predicting hydrodynamic performance agrees well with the experimental data.