This study takes biophysics--a relatively new field with complex origins and contested definitions--as the research focus and investigates the history of disciplinary formation in twentieth-century China. The story of building a scientific discipline in modern China illustrates how a science specialty evolved from an ambiguous and amorphous field into a full-fledged academic discipline in specific socio-institutional contexts. It focuses on archival sources and historical writings concerning the constitution and definition of biophysics in order to examine the relationship between particular scientific styles, national priorities, and institutional opportunities in the People's Republic of China. It argues that Chinese biophysicists exhibited a different style of conceiving and organizing their discipline by adapting to the institutional structure and political economy that had been created since 1949. The eight chapters demonstrate that biophysics as a scientific discipline flourished in China only where priorities of science were congruent with political and institutional imperatives. Initially consisting of cell biologists, the Chinese biophysics community redirected their disciplinary priorities toward rocket science in the late 1950s to accommodate the national need of the time. Biophysicists who had worked on biological sounding rockets were drawn to the military sector and continued to contribute to human spaceflight in post-Mao China. Besides the rocket-and-space missions which provided the material context for biophysics to expand in the late 1950s and early 1960s, Chinese biophysicists also created research and educational programs surrounding biophysics by exploiting the institutional opportunities afforded by the policy emphasis on science's role to drive modernization. Biophysics' tie to nationalistic and utilitarian goals highlights the merits of approaching modern Chinese history from disciplinary, material, and institutional perspectives.