In democratic Brazil, political participation has been characterized by the enlargement of civil society's presence in public policies. Such presence generated a series of institutions with the participation of civil society and state actors in the areas of social welfare, health and urban policies. Within these institutions, it began to happen what we can call an institutionalized representation of civil society. This representation is characterized by the inexistence of an explicit requirement of authorization, and the absence of a structure of territorial monopoly in the representation carried out by the actors of civil society. Representation by affinity is proposed as a manner of associating parliamentary representation and representation of civil society.