He received his Ph.D. degree in history in 2005 from Renmin University of China. His academic interests include U.S. Constitutional History and History of Immigration to the United States. Recently, he works on a research project “Development of U.S. Horizontal Federalism”, which is based on the clauses concerning interstate relations in U. S. Constitution and the efforts taken by several states to compete or cooperate among themselves. While at CSLS, he will continue this research, and particularly he will focus on the part “Horizontal Federalism and Environmental Regulation”. (10/16-08/17) yangchengliangly@126.com