The purpose of this study is to reinterpretate the history of nursing and health care from the viewpoint of post-structuralism. It has been emphasized that the development of modern health care has been due to the progressive efforts of medicine and to medical discoveries. Medicine has dominated the history of health care rather than nursing or other health professions. The present study adopts the post-structural method by Foucault, which tries to unite language and knowledge. Foucault examines "the institutionalization of knowledge and the power exerted thereby, with special reference to the devices of social regulation and their function over the madness, the disease, the crime, and the sexuality." The concept of power in Foucault's writing is that it is exerted spontaneously in verbal behaviors of individuals through knowledge of everyday life such as definition of body or mind, sexuality and relation ship of family. Therefore as to the problem of power, this study tries to understand the meaning of the health care history through an analysis of the formation of medical discourse. In order to have authority in a power relation, the medical professional asserts that medical discourse in the most scientific knowledge. The authority of medical professionals can be reinforced by the fact that male medical professionals outnumber female. Devaluation of nursing care is reinforced by the medicine which has the legitimate through use of the political skills.