peer reviewed ; The maps 2 to 17, drawed in UTM coordinates, show the pattern of distribution of several species of small mammals in eastern Belgium. Biogeographic data were colleted by means by barn owl pellets analysis. Many traps also places inside the natural reserve "Les Hautes Fagnes" in order to compare the small mammal fauna of this area with th eastern Belgian fauna. Traps were set in spruce forests, turf moors, bilberry moors which are the most important biotopes in the "Les Hautes Fagnes". In this area, we don't find some man linked species like the rats (Rattus), the house mouse and the white toothed shrews (Crocidura). The common vole, Microtus arvalis, also seems to be lacking in this area. A list of the different small mammals species living in eastern Belgium is given. The species with a mark + are those we've found in the area of "Les Hautes Fagnes" (square KB80 and KB90 in UTM code).