- 1969 - Intern, Chiang Mai University Hospital
- 1970-1973 - Resident in Internal Medicine, Fac. Med., Chiang Mai University
- 1974-1977 - Instructor, Department of Medicine, Fac. Med.Chiang Mai University
- 1978-1996 - Assistant Professor, Department of Medicine, Fac. Med, Chiang Mai University
- 1997-2001 - Director, Research Institute for Health Sciences,Chiang Mai University
- 2001-2005 - Deputy Head, Department of Medicine Chief, Division of Infectious Disease of Tropical Medicine Faculty of Medicine, Chiang Mai University