The objective of this work is to answer how the interaction networks of municipalities can contribute to the promotion of local socioeconomic development? To this end, it was made the definition of interaction networks, i.e., they are formed by local actors, understood in public sector, private sector and third sector, able, through their articulation in movement of cooperation and solidarity, to contribute to the local socioeconomic development. And, to understand them, in addition to documentary and bibliographical analysis, we used the case study of two small municipalities: Sao Domingos do Prata and Antonio Dias, and a large one: Coronel Fabriciano. What was found in such research is that local actors act in isolation, often only in favor of meeting particular demands, not mobilizing in networks for development. Thus, decision-making does not happen as desired, there is no responsible protagonist for the articulation of these local actors, and often occurring to the disregard of their demands by factors of political and economic order.