Abstract: The academic focuses on the publicity in the series of enlightenment and reflection system, such as, open rather than closed, rights and responsibilities, communicative ration and intersubjectivity. The publicity is not reflected in the direct expression, but rather in the discourse on the defense of society for Foucault in the field of sociology of knowledge. In Foucault's studies,society consists of the public, knowledge, power, significance of the enlightenment of the modern. And on the sociology of knowledge, it refers to a series of social facts, that is, the conventional areas of knowledge should be reflected in the study. The powers that constitute a social structure should be reviewed. The rational enlightenment also requires reflecting and criticism. The publicity of knowledge, power and the enlightenment is the issue of Foucauh's perspective. Foucauh believes the knowledge carried flips and the expanding object is the key to defending the publicity.