Liu Jun, one of the world’s foremost statisticians and a long-time Harvard professor, has returned to China full-time, taking up a prestigious chair at Tsinghua University last month. The move marks the return of an academic whose career spans data science, biostatistics, and artificial intelligence, and whose early life reflects a complex interplay between intellectual ambition and political engagement.
In 1988, Liu transferred from Rutgers University in New Jersey to the University of Chicago to study under statistician Wing Hung Wong. While there, he became deeply involved in human rights issues, dedicating significant time to student activism. Although the student movement he supported did not take place in Chicago, it was tied to the massive demonstrations in Tiananmen Square in Beijing in 1989, with overseas student groups organizing supportive events. Liu’s mentor once asked him whether he wanted to be “a politician or a mathematician?”
This question proved pivotal. After reflection, Liu chose to dedicate himself to mathematics. In 2001, he reflected on his youth in an interview with Harvard University’s Harvard Gazette, stating, “I didn’t want to solve problems just because they hadn’t been solved by others. I wanted to connect to reality. Although I didn’t know exactly what statistics was, the field appealed to me for that reason.”
On August 30, despite his history of student activism, Tsinghua University formally announced Liu’s full-time appointment. Qiu Yong, Communist Party secretary of Tsinghua University, and Li Luming, the president, attended the high-profile ceremony, which was hosted by Vice-president Jiang Peixue. Liu was appointed as the “Tsinghua University Xinghua Distinguished Chair Professor,” the university’s highest honor, previously awarded to only two top overseas-returned scientists.
Born and raised on the Tsinghua University campus, Liu developed an early fascination with mathematics under the guidance of his father, a university teacher. Growing up during the latter years of the Cultural Revolution, developing such interests was extraordinarily difficult—computers and calculators were scarce, and even mathematics books were hard to come by. To support Liu’s studies, his father borrowed books from various sources and even hand-copied them for his son.
“I couldn’t tell high school from college texts, so I read everything,” Liu recalled in a 2012 interview with Science News Daily. “Doing maths was like a game you could play with only a piece of paper and a pencil. On Sundays, I rode my bike for an hour to meet friends and do problems.”
Liu was accepted to Peking University, where he spent much of his time playing bridge and socializing. Yet upon graduating in 1985, he ranked among the top students in the mathematics department. He was awarded a scholarship by the Society for Industrial and Applied Mathematics and moved to the U.S. with a cohort of exceptional Chinese mathematics students.
Liu’s early American life at Rutgers University in New Jersey presented a language barrier, but his mathematical talent transcended words. “Fortunately, I could get by with understanding formulas and equations,” he told the Harvard Gazette. “I got straight As without knowing much of what the teachers were saying.”
In 1988, Liu transferred to the University of Chicago, refocusing on mathematics, particularly statistics. He completed his PhD in 1991 within three years—despite also engaging in student human rights activities—and was immediately offered an assistant professorship at Harvard University. He later served on the West Coast at Stanford University as assistant, associate, and full professor before returning to Harvard in 2000 as a tenured full professor in the Department of Statistics.
Liu has contributed significantly to bioinformatics, biostatistics, and computational biology, leaving a profound impact on big data processing and machine learning. He received the COPSS Presidents’ Award in 2002, the Morningside Medal in Applied Mathematics in 2010, and the Pao-Lu Hsu Award from the International Chinese Statistical Association in 2016. Liu became a Fellow of the American Statistical Association in 2005 and was elected to the National Academy of Sciences in May 2025.
Since 2005, Liu has served as a visiting professor at Tsinghua University. In 2015, he led the establishment of the Tsinghua University Centre for Statistics and became its honorary director. More recently, in July last year, he became director of the Development Committee, leading the creation of the Department of Statistics and Data Science and helping recruit outstanding overseas faculty.
Liu’s decision to return to China seems long considered. At a Peking University alumni forum in New England in November 2010, he was asked about returning. Although his “roots” were in China, where his parents were aging and the country’s rapid economic growth was promising, he hesitated due to his children living in the U.S. Fifteen years later, influenced by China’s technological development and Harvard funding cuts under the Trump administration, he decided to return.
The Trump administration froze grants to Harvard on April 14, halting work on numerous research projects critical to national and global development. “Choosing to return now is driven by a love for education and scientific research, as well as a sense of patriotism,” Liu said at his Tsinghua welcome ceremony on August 30. “Statistics and data science are important methods and ways of thinking in transdisciplinary, and they are a crucial foundation for the development of artificial intelligence, possessing vast prospects.”
Tsinghua officially established the Department of Statistics and Data Science on July 10. According to the university, this is a key step to refine its academic structure, support the national big data strategy, advance AI initiatives, and contribute to the Digital China initiative.
