Patterns and functions of European landscapes should be strongly modified by the changes of agricultural activities and by the way they will react to the new European agricultural policies after 2013 and the CAP redefinition. In that context, models of interactions between agricultural practices and ecological dynamics are of great relevance for considering the potential changes in landscape structures. In previous research actions, our team developed scenarios of landscape and policy change, as well as simulations of landscape change. At that stage, we wanted to develop a more integrative and participatory approach for simulating landscape ecological dynamics and farms socio economic changes in order to allow stakeholders to build their own scenarios according to their identified needs. The first objective of this text is to explain why our models have properties that make them simulators adapted to participatory approaches for scenario building. The cellular automaton Genevrier simulates the evolution of land cover. All transition rules can be displayed and modified by stakeholders during working sessions. The socio-economic simulator Larzac allows simulating the consequences on farm income of scenarios defined with stakeholders and based on information describing the farming system. The second objective is to present the potentialities of using both simulators as complementary tools for considering alternative agro-environmental policies.