Based on an ethnographic survey of three ecological initiatives in French poor neighborhoods, this thesis examines the social and territorial conditions of the anchoring of ecology in an impoverished urban context. It is in line with the critical work of post-materialist theory, which reduces ecology to a concern of the wealthy classes. It highlights the mobilizing potential of an ordinary ecology that involves the concrete and collective transformation of ways of living and inhabiting, and that moves away from both protest struggles and small individual actions. This ecology allows a re-articulation between ecology and social question through a re-appropriation of the daily life. Ordinary ecology is not a popular ecology: it does not only ...