The technology of SFE(Supercritical Fluid Extraction) is a new subject from Modern Chemicals Industries, which is one of the advanced Separation Technology. As for SCF(Supercritical Fluid), it is was that fluid on Critical Point(Pc, Tc) under Thermodynamic State,  the Critical Point is the state point when interface of Gas and Liquid disappear, which process very novel physical& chemical characters. It density degree close to liquid, viscosity degree close to gas, but bigger diffusion coefficient &dielectric constant, smaller viscosity etc. these characters have contributed to good separation effects. So the SFE is mainly about Separation,  the solution will touch with extracted materials under High Pressure& Suitable Temperature, the Solutes would be diffused into the solution, then change the operation Conditions, to make the Solutes separate out.