| 2003-2009 | Director, Graduate Institute of Clinical Medicine, Medical College, National Taiwan University |
| 2001-2003 | Director, Hepatitis Research Center, National Taiwan University Hospital |
| 1994~ | Professor of Medicine, Graduate Institute of Clinical Medicine, Medical College, National Taiwan University |
| 1993~ | Professor of Medicine, Graduate Institute of Microbiology, Medical College, National Taiwan University |
| 1992~ | Attending Physician, Division of Gastroenterology and Hepatology, Department of Internal Medicine, National Taiwan University Hospital |
| 1991-1992 | Fellow, Division of Gastroenterology and Hepatology, Department of Internal Medicine, National Taiwan University Hospital |
| 1987-1990 | Resident, Department of Internal Medicine, National Taiwan University Hospital |