The Nanjing Branch is an administrative organ of the Chinese Academy of Sciences (CAS). The branch coordinates activities of CAS research institutes in Jiangsu Province and manages cooperation between CAS and the Provinces of Jiangsu and Jiangxi. It was formally established in 1978 based on roots extending back to 1950.  

The Nanjing Branch oversees 10 institutions, namely, the Purple Mountain Observatory, the Nanjing Institute of Geology and Paleontology, the Nanjing Institute of Soil Science, the Nanjing Institute of Geography and Limnology, the Nanjing Institute of Astronomical Optics and Technology, the Suzhou Institute of Nano-tech and Nano-bionics, the Suzhou Institute of Biomedical Engineering and Technology, the Nanjing Astronomical Instruments Company, the Ganjiang Innovation Academy and the Institute of Botany of Jiangsu Province and CAS. 

The institutes under the Nanjing Branch boast 3 State Key Laboratories, 2 National Engineering Laboratories and 17 field observatory stations, including 5 national key observatory stations. After years of development, these institutes have achieved important research results in 20 fields and 30 specialties.

By the end of 2020, the Nanjing Branch had 2696 personnel, including 1,900 scientists and technicians, of whom 407 are professor-level researchers and 643 are associate professor-level researchers. Within the Nanjing Branch are 10 CAS and CAE academicians. In addition, 38 individuals are supported by the National Science Fund for Distinguished Young Scholars.

The Nanjing Branch administers 39 master programs and 25 Ph.D. programs. By the end of 2020, the enrollment was 2,076, of which 862 were Ph.D. students.

The Nanjing Branch coordinates cooperation between its institutes and the Provinces of Jiangsu and Jiangxi. By the end of 2020, the branch had signed comprehensive science and technology cooperation agreements with 13 provincial cities in Jiangsu, covering all cities and counties in the province and nearly all the research institutes under the Nanjing Branch. In addition, the Nanjing Branch is home to nearly 200 R&D units constructed by local government, enterprises, universities and CAS.

The institutes under the Nanjing Branch publish more than 10 academic journals. Among them, Pedosphere is catalogued by SCI. It is the only English academic publication on soil science in China. The Chinese Astronomy and Astrophysics is catalogued by SCIE.