This book is the first monograph to study the processes of establishing and reconstructing the academician system, and the landmark events in the history of science and technology in 20th century China. It also provides new insights to help us understand the process of scientific institutionalization in modern China. Drawing on detailed archive records, it discusses the process of the establishment of the Academia Sinica's academician system in the Republic of China, as well as the unique and tortuous transformation process from members of the Academic Divisions（学部委员）to academicians of the Chinese Academy of Sciences（中国科学院）in the People's Republic of China. These play an important part of China's modernization process, and reflect scientific institutionalization in China.  The book also highlights the fact that under the leadership of the government, the academic elite became participants in the construction of national academic system after the founding of the People's Republic of China.