Abstract: The process for solanesol extracting from tobacco leaves with Supercritical Fluid CO₂ was studied. The factors affecting the process were researched including temperature, pressure, the flow-rate of CO₂, the manner of extraction, entrainers and its adding manner. The optimum extraction conditions of solanesol were investigated by orthogonal design of four factors and three levels with the goal of solanesal extraction yield. It was found for a more accurate determination method of free solanesol in tobacco leaves and the extracted anthraquinones were analysed by high-performance liquid chromatography(HPLC).It was the goal to study the method of improving the extraction yield of solanesol,and provide certain guidance of the industrialized production.The results show that the optimum extracting parameters were: methanol as entrainer, the flow-rate of CO₂ at 15 kg·h^-1, temperature at 45℃ and pressure under 25 MPa，Under optimal extraction conditions,the extraction yield of solanesol was 92.1%.

Key words: supercritical fluid extraction, solanesol, entrainer, tobacco leaves, carbon dioxide