In a context of general reform of public policies and of adaptation of the tool of Defense to new geostrategical pressures, military brownfields are becoming more numerous. In the past, the city used easily the land space on its fringes. While it is today trying to rationalize the urban network in the frame of sustainable development. It is more interested in its derelict lands and it tries to set up a logic of urban regeneration which could be applied to all these wastelands, whatever is the nature of their initial activities. Among these sites waiting for reconversion, the urban military wastelands could give real opportunities as part of regeneration by being renewed and so participate to the urban renewal. The article below proposes to consider how the military urban brownfields can an opportunity for the territory.