Sun Qixiang, dean of the school of economics at Peking University, said Xia Yeliang "just wasn't a good teacher," The New York Times reported Friday.
"Politics had noting to do with this decision," Sun added.
The school's faculty voted 30-3 two weeks ago not to renew Xia's teaching contract. He has criticized China's powerful propaganda minister and demanded an end to one-party Communist rule.
Sun and three economics professors defended Xia's termination Friday. During his decade at the university, they said he had been urged to improve his teaching style and had published only one academic paper. He also had been ranked three times as the worst professor, receiving 340 negative reviews from students.
Xia, 53, responded that he had been told only once of his lackluster ranking, noting that 340 bad write-ups represented a small portion of the thousands of students he had taught.
The decision has been condemned by the Committee of Concerned Scientists and faculty at universities around the world have called for a review of collaborative agreements with Peking University.
Thomas Cushman, a sociologist at Wellesley College which has an educational partnership with Peking University, says he hopes to offer Xia a two-year fellowship if Wellesley administrators approve.