Abstract : Periurban spaces represent a significant and growing part of the french spaces : they accommodate 16,9 % of the total population. This work intends to analyze from a geographical perspective the social innovation processes currently at work in this territories. Its aim is to show that the spatial organization of rural periurban spaces north of Montpellier allows and requires the emergence of social innovations. The co-implication of local/global rural/urban spatial characteristics creates both ambivalent et complex spatial organization. It tends to initiate innovation processes. Spatial organization produces two typical innovations. The first one is similar to the modern society innovation : unstable, flexible, ephemeral. The second one is specifically periurban : it is construed with proceeding to a selection between the ambivalent spatial characteristics. Furthermore, innovation play an important part in the spatial change processes. The identification and the analysis of a system of periurban innovation shows that : - The imbrication of personnal, economic, spatial activities, individual and collective projects, organizational and institutional innovations, lead spatial change dynamics. - economic innovation dynamics lead more specifically spatial change system. Institutions play a specific and important part in the expansion and perpetuation of innovation.