The "Building a cross-border eco- citizenship" project brings together youth workers and relevant actors on volunteering from the four countries and five regions that make up the Greater Region: Lorraine in France, Luxembourg, Rhineland-Palatinate and Saarland in Germany, Wallonia and the German-speaking Community in Belgium. Together we will share our best practices and working methods to achieve the development of a new independent program of eco-citizen commitment to youth in the Greater Region: the “Eco-Citizen Service in the Greater Region”. We therefore focus on mobility in cross-border region, on the voluntary commitment of young people, on the education for sustainable development and the environment, on the emergence of Eco- citizenship awareness in the Greater Region.As part of the elaboration of a new volunteer program, we will also develop:• the administrative , financial and operational framework ; • the educational tools for youth workers, young volunteers and the actors active in the environmental field ;• A communication strategy and the related tools (website, social network etc...);• information events for all target groups of the project.We also want to: • encourage cross-border mobility of young people not necessary linked to the school or to their free-time; • give them the opportunity to acquire new skills and knowledge at both local and European level; As the main objective is to develop a new independent program of eco-citizen commitment to youth in the Greater Region, the strategic partnership will be the way to establish a good cooperation between the partners and a sustainable and independent volunteer program, doomed to exist in the long term. This project could be a model for other border regions in the European Union or for similar cooperation.