In spatial planning, soil quality data is poorly considered when it comes to design urban planning documents. However, there is a growing concern about urban renewal and urban sprawl limitation, as well as about biodiversity conservation within urban areas. In this respect, assessing soil quality in order to better conceive more sustainable urban plans becomes an objective in the agenda. The poster presents the UQualiSol-ZU Project (funded par the French Ministry of Ecology, GESSOL Program) aiming at investigating whether and how scientific knowledge on soil quality could be included into land use planning. Its objectives were: 1) to assess the expansion of urbanization in a given territory, and what planners do about soil quality, 2) to analyse the existing regulations to identify how such soil quality could be taken into account, and 3) to investigate which kind of knowledge could be used by planners. Its ultimate goal was to design an index displaying how relevant land use is, given the multiple soil potentialities. This methodology was developed on two periurban municipalities next to Marseille (Southern France).