Abstract: Sophora flavescens Ait. is a traditional Chinese medicine thathas been used for the treatment of various diseases for centuries. Matrine-type alkaloids are the primary active substances that can be used in medicine and pesticide. In this paper, supercritical carbon dioxide (SC-CO2) was used to remove lipid-soluble substances so that a cleaner sample of S.flavescens was available for extraction of matrine-type alkaloids. The recovery of lipid-soluble substances (R1) and the recovery of matrine-type alkaloids (R2) were investigated. Parameters of supercritical fluid extraction (SFE), such as pressure, temperature, time and their effects were evaluated. Furthermore, a comparison between this method and the direct solvent extraction method was made, and an average of 72%higher yield of matrine-type alkaloids was obtained by the former method. Thehigh yield of matrine-type alkaloids was obtained at pressure 12-18 MPa, temperature 60-75℃ for 2h.