http://www.law.northwestern.edu/news/article_full.cfm?eventid=2757
At university he worked very hard, and received a bachelor's degree four years later. He continued as a graduate student for a master's degree at Renmin. After graduation he became a teacher at his university for four years, then went to the United States twice to study at the law school of Northwestern University, where he got his doctoral degree in 1993.

While on average it takes three to five years to get such a degree, it took He only a little more than one year, something of which he is intensely proud. Then by the end of 1993 he returned to Beijing to continue his teaching career.

http://www.law.northwestern.edu/news/article_full.cfm?eventid=2973
He went to the US with his wife and daughter in the autumn of 1992 on a scholarship and received his doctor of juridical science from the Northwestern Law School in a little more than a year. "I was told I had broken some kind of record," he says. "Generally speaking, to get an SJD requires three to five years."