Abstract-- Great emphasis has been recently given to agentoriented methodologies for the construction of complex software systems. In this paper two approaches for the construction of agent-oriented methodologies and based on methods integration are presented: meta-model-driven and development process-driven. The former is based on the MAS meta-model adopted by designers for the development of a MAS for a specific problem in a specific application domain. The latter is based on the instantiation of a software development process in which each phase is carried out using appropriate method fragments and by the mutual adaptation of the work products coming out from each phase.