Abstract: Supercritical CO2 extraction is a new subject of separation techniques and develops rapidly in recent years becauseof its advantages over conventional extraction methods. However, there are still some problems unsolved with it,such as highoperation pressure,long extraction time,relatively low extraction yield etc., so that it could not be used widely on industrial scale.Since modifier can enhance supercritical CO2 extraction process and be used to solve the problems mentioned above, it becomesa new orientation of research on supercritical CO2 extraction. The effect and principle of the modifiers on the supercriticalCO2extraction were introduced and the impact of the property of modifiers(molecular polarity、molecular weight、molecularphysical volume) on the supercritical CO2 extraction were analyzed in this paper. The profile of extraction yield against property ofthe modified can be summarized:The higher the polarity of the modifier,the higher solubility of solute in supercritical CO2.Increase of molecular and/or molecular physical volume will result-in decrease of solubility of solute in supercritical CO2 andconsequently the decrease of the extraction yield. In case the modifier contains special molecular structure that facilitates theformation of hydrogen bond,the extraction yield will increase.

Key words: supercritical CO2 extraction, modifier, molecular characteristics, fortified extraction