Brazilian Third Sector has been reconfigured to approach the social businesses and their respective support institutions. Social entreprises are hybrid organizations that seek to address socio-environmental problems based on business models governed by market mechanisms. They differ from non-governmental organizations because they do not rely on philanthropic resources or donations; they do not fit as traditional companies because they have as main success measure the social impact of their actions, not only profit; they distance themselves from corporate social responsibility initiatives because of the fact that their positive results do not come from mitigating a negative externality or from actions that are core business disassociated. The thesis analyzes the university business incubators that host such startups social businesses. They are bureaucratic institutions with complex nature and interconnections, that can conform typological modalities guided by the nature of their maintainers - private, public and community. The research is comparative and multicases with a methodological route that aggregates historical, theoretical-conceptual inputs, institutional analysis and research with incubator managers: eight respondents (representing four incubators) as direct interlocutors and 26 others as indirect interlocutors that were reached by electronic form application at a distance (representing 25 incubators). The university business incubators with community maintainers demonstrated a better performance in the execution of operational, managerial and strategic processes (maintenance and investment of infrastructure; current expenses, preparation of legal documents, hiring of personnel; change of strategic positioning), among other attributes associated with international incubators performance parameters, entrepreneurial culture, flexibility of incubation of new market niches (including social entreprises).