Pogostemon cablin (patchouli) is a plant of the Lamiaceae family. The clinical efficacy of Patchouli product is to resolve dampness with aromatics. It is mainly used for treating Retention of Damp-Turbid Substance (Shi Zhuo Zhong Zu), Summer heat-Dampness lassitude (Shu Shi Juan Dai), Thoracic Disconfort (Xiong Men Bu Shu), Internal Retention of Cold Wetness (Han Shi Nei Zu), Abdominal Pain Diarrhea (Fu Tong Fu Xie), Nasosinusitis Headache (Bi Yuan Tou Teng), and so on. The pharmacological studies indicated that the essential oil from Pogostemon cablin showed strong adjust gastrointestinal function, insecticidal activity, antibacterial activity, anti-inflammatory and analgesic effect. In this thesis, preparative isolation and purification of compounds from essential oil of Pogostemon cablin used high performance centrifugal partition chromatography and traditional separation methods. There are mainly three chapters for the thesis. Chapter I introduced the background and strategy for the present study. It is a review for the study on chemical constituents and pharmacologic actions of the essential oil of Pogostemon cablin and so on. ChapterⅡintroduced the research on separation and identification the chemical constituents of the essential oil of Pogostemon cablin using traditional separation methods. The separation of essential oil of Pogostemon cablin was carried out by using silica gel column, pre-HPLC, HPLC and so on. Chapter III introduced the experiment on preparative isolation and purification of compounds from essential oil of Pogostemon cablin using high performance centrifugal partition chromatography. The method of one-step separating patchouli alcohol from the essential oil of Pogostemon cablin was established for the first time. Key words: Pogostemon cablin; essential oil; patchouli alcohol; high performance centrifugal partition chromatography (HPCPC); sesquiterpenoid; monoterpenoid