2012- Tenure-Track Assistant Professor, Department of Public Health, College of Health and Human Services, Western Kentucky University, Bowling Green, KY, USA.
2011-2012 Adjunct Faculty, Department of Health Administration, Public Health and Gerontology, School of Public Service Leadership, Capella University, Minneapolis, MN, USA.
2008-2011 Assistant Professor, Division of Epidemiology, Department of Community Health, Saint Louis University School of Public Health, Saint Louis, Missouri, USA.
2003-2007 Visiting Fellow of Cancer Epidemiology, OEEB, Division of Cancer Epidemiology and Genetics,US National Cancer Institute, National Institutes of Health (NIH), Rockville, Maryland, USA.
2002-2003 Research/Teaching Assistant, data search and management, Department of Epidemiology, Johns Hopkins University Bloomberg School of Public Health; data management and data analysis in the Emergency Department, Johns Hopkins School of Medicine, Baltimore, Maryland, USA.
2000-2002 Research Assistant, Environmental Toxicology and Molecular Medicine Program, Clemson University, Clemson, South Carolina, USA
1996-2000 Assistant Professor and Director of Food Toxicology Program, Department of Food Sciences and Engineering, Zhejiang Gongshang University, Hangzhou, Zhejiang Province, P.R. China.
1994-1996 Research Associate, Department of Toxicology, Zhejiang University School of Public Health, Hangzhou, Zhejiang Province, P.R. China.
1992-1994 Faculty, Department of Epidemiology, Zhejiang University School of Public Health, Hangzhou, Zhejiang Province, P.R. China.
1991-1992 Residence/Intern in Preventive Medicine, Centers for Disease Control and Prevention in Xia- Cheng District, Hangzhou, Zhejiang Province, P.R. China.
1990-1991 Residence/Intern in Clinical Medicine, Railroad Ministry Hospital in Hangzhou, Zhejiang Province, P.R. China.