The dissertation entitled The democratic administration of the city, local power and urban plan: the case of the city of Rio das Ostras focuses the process of the democratic administration in the process of constructing the rules categories of the urban plan law, pointing out the legal control of the cities citizenship rights in the large field of the human rights, concerning the Habermas communicative action theory. For democratic administration we understand the engagement of the citizens and inhabitants of the city in the activities of projection, control and valuation of the urban politics, which is a condition of the urban plan, ruled in the federal urban law - The Estatuto da Cidade. The complete accomplishment of the democratic administration is a fundamental guarantee for protecting the Estatuto da Cidade of being a non desirable instrument of technical conceptions, giving it its real destination, which is to promote the city rights for all the citizens. In this dissertation, these theory suppositions are valid through a concrete study of case which refers to the experience of democratic elaboration of the propose of a law, presented by the Executive to institute the Rio das Ostras Urban Plan. The present work is the result of an interdisciplinary approach and considers the constitutional principles and the mandatory provisions of the Estatuto da Cidade and its theory and methodological proposes, in the process of producing a real meaning for the urban rules.