1982- 1984: Assistant Professor, Department of Mathematics and Physics, Jilin University of Technology.
1984- 1987: Graduate student of Changchun Institute of Geography, China Academy of Sciences (now Northeast Institute of Geography and Agroecology), with a master's degree in remote sensing and mapping.
1987- 1990: Assistant Research Fellow, Changchun Institute of Geography, China Academy of Sciences (now Northeast Institute of Geography and Agricultural Ecology).
1990- 1992: Master of Natural Resources Management Engineering Department, University of Connecticut.
1992- 1995: Master of Natural Resources Management Engineering, University of Connecticut, USA, with a doctorate.
1990- 1995: graduate research assistant, Department of Natural Resources Management Engineering, University of Connecticut, USA.
1995- 1999: Assistant Professor, Department of Geography and Anthropology, University of Illinois at Chicago, USA.
1999- now: Professor, Department of Natural Resources Science, University of Rhode Island, USA (tenure)