A new on-line coupled supercritical fluid extraction(SFE) with high performance liquid chromatography(HPLC) system was developed.Two three-port valves were used as an interface to connect SFE and HPLC.In this design,the two important processes including sample preparation and sample analysis were(integrated) into a system.Compared with off-line system,the on-line system has many advantages,such as high sensitivity,short analysis time,avoiding sample pollution,easily operation and ease to automation etc.Its application in the extraction and analysis of triterpenoids to the fruiting bodies of Ganoderma Lucidum was also described.Under the optimized extraction conditions,the similar chromatogram of the extract with on-line SFE- HPLC system was observed as well as that with off-line SFE followed by HPLC.The result showed the great potential of the on-line system in the extraction and analysis of tradition Chinese medicine.