There is no clear official scope of "nine key universities" in China, but there is a C9 alliance, which includes Peking University, Tsinghua University, Fudan University, Shanghai Jiaotong University, Nanjing University, Zhejiang University, China University of Science and Technology, Harbin Institute of Technology and Xi Jiaotong University. C9 is the first top university alliance in China, which was established in June 2009. The members of the alliance are the first batch of first-class universities under the "985 Key Construction" in China, including 9 universities including Peking University, Tsinghua University, Fudan University, Shanghai Jiaotong University, Nanjing University, Zhejiang University, University of Science and Technology of China, Harbin Institute of Technology and Xi Jiaotong University.

The nine-school alliance is similar to the Ivy League in the United States, aiming at strengthening cooperation and exchanges in the fields of personnel training and scientific research, and complementing each other's advantages. Known internationally as "China Ivy".