Based on extended research on Chinese medical and epidemiological archival material dating back to the beginning of the 20th century, and on six months of internship in epidemiology in Beijing’s Medical School and in Haidian District’s Centre of Disease Control and Prevention, this thesis explores the conjunction of three major epidemiological crises in modern Chinese history with processes of State formation: the 1911 Manchurian pneumonic plague, the 1952 germ-warfare, and the 2003 SARS outbreak. Analysing the three crises as Events in line with Alain Badiou’s epistemology it seeks to establish how different strategies of governmental fidelity to the imagined cause of each crisis have led to distinct modes of organisation and valorisation of the social: Republican China and its decline to fascism; the clash between professional revolutionaries and technocrats in Maoist China; and the emergence of the “Harmonious Society” of mass exploitation and repression today. This conjunction between State formation and epidemiological Events is explored with the use of Foucault’s genealogical method in a quest for a historical materialist approach that posits at its epicentre processes of class composition, decomposition and recomposition, and their contested enclosure by the governmental apparati of capture. The present thesis thus examines the three major epidemiological crises of modern China as forming grounds for biopolitical strategies that give rise to modes of subjectivation and circuits of debt/guilt within the context of the class struggle. And at the same time, it aims to create a new field of investigation for anthropology: the relation of State and Event, from a viewpoint that contests the accepted relation of event and structure expounded by Marshall Sahlins, proposing as the main object of this investigation the conjunction between necessity and will that can never be reduced either to the naturalism of historical determinism, nor to the culturalism of subjective contingency.