Abstract: Technique of supercritical carbon dioxide extraction(SCDE) of ursolic acid in Rabdosia rubescens (Hemsl.)Hara was studied.The optimal extraction conditions were achieved for 1 kg material as follows:extracting pressure 20 MPa, size of granules 40 mesh, extracting temperature 40℃, CO₂ flow rate 15 L/h, extracting time 3 h, modifier 95% alcohol,at dosage of 30% of raw material.The yield of product is 4.17%. The content of ursolic acid in the product is 6.24%determined by HPLC. The result shows that the method has the advantages of simple operation, less solvent consumption, short extraction time, high extraction yield and no interference of impurity during determination.

Key words: supercritical carbon dioxide extraction, Rabdosia rubescens(Hemsl.)Hara, ursolic acid