Setting-up of a soil monitoring system in Walloon Region anticipating the future European directive on soil. The European Commission currently finalizes its Framework Directive for soil protection waited for the end 2004. The project ARVA of the Walloon Region aims setting up the monitoring of arable land. The project proceeds in four phases: (i) the development of a soil monitoring which complies with the requirements of both the European regulation and the Walloon agriculture practices; (ii) the inventory of existing knowledge on the quality of soil in the Walloon Region and their relevance at Regional scale; (iii) the best estimate of the accuracy needed to detect evolutions in soil. To do this, test sites will help to validate the methodology used; (iv) an analysis of the strategies for structuring a future monitoring network. This strategy depends on the threat taken into consideration, as the selected options shall not compromise future needs for monitoring.