A spatiaused typology of farm systems :a tool of regional diagnosis of agriculture application to the cereal farms of the west Marshlands The spatialisation of a typology of functioning was made through the regional diagnosis of the cereal farms of the Rochefort and Poitou marshlands. The realised typology is based on different strategies of management, and particularly on marketing. The distribution of these types in the space is not homogeneous but depends on two main criteria : physical background and economic environment Linking territory to typologies of functioning seems particularly interesting. Indeed, it permits to take in account the notion of potentialities of evolution of the farm (linked to its type and to its territory). Moreover, this tool of regional diagnosis permits to treat problems needing collective solutions.