Liu has been a Distinguished Research Fellow at the Research Center for Environmental Changes, Academia Sinica, Taipei, China since 1999. He is the founding Director of the Center. Liu has made fundamental contributions in atmospheric chemistry, air pollution and climate change. He has published more than 160 papers which have received more than 6500 citations. He is one of the first few Chinese geoscientists in the prestigious ISI Highly Cited Researchers list. He was elected as an Academician of Academia Sinica in 2012. He was elected a Fellow of the American Geophysical Union in 1994. He is also a Fellow of the Chinese Meteorological Society. In addition, Liu served as Editor-in-Chief of the Journal of Geophysical Research-Atmospheres (JGR) from 1988 to 1991.

Liu is a Distinguished Research Fellow at the Institute of Atomic and Molecular Sciences, Academia Sinica in Taipei, Taiwan. His work in reaction dynamics has led to new fundamental insights into the intricate details of elementary chemical reactions under crossed molecular beam conditions, including the first unambiguous observation of reactive or Feshbach resonances, the quantum state correlation of product pairs in a reactive event, the mode- and bond-selected reactivity of polyatomic reactants, and the stereo-control of bimolecular reactions. He is a member of Academia Sinica, a fellow of American Physical Society and Royal Society of Chemistry, the recipient of the Distinguished Alumni Award of the National Tsing Hua University, the First Presidential Science Prize of Taiwan, the Alexander von Humboldt Research Award, and the R. B. Bernstein Award.

Lee is Dist. Res. Fellow, Inst. of Information Sci., Academia Sinica, Taiwan, (1998- ), and was Dir. of IIS (1998-08), and Pres. of Natl. Chung-Hsing U. (2011/8-2015/7). He is also Dist. Res. Chair Prof. of computer science, Natl. Taiwan U., and Chair Prof., Natl. Taiwan Tech and Natl. Chung-Hsing U.. He was Professor of computer science, Northwestern U. (1978-98) and was Program Dir., CISE, Natl. Science Foundation (1989-90). He is editor of Algorithmica, Intl. J. Information and Computer Security; Co-Editor-in-Chief, Intl. J. Computational Geometry and Applications; and editor, Lecture Notes Series on Computing, World Scientific Publishing Co., Singapore. He is Fellow of IEEE and ACM; Academician, Academia Sinica, Taiwan, recipient of the Humboldt Research Award, Germany, and Dist. Educator Award and Illini Comeback Guest Award, U. of Illinois, Urbana-Champaign, IL, USA.