Abstract. During a special mapping in the tidal flat of Eastern Frisia the question arose as to how the soils in this area could most suitably be classified and represented on maps (grain size mixtµres). The grouping suggested in this paper is done according to chemical and physical properties of these recent tidal flat sediments. Simultaneously conformity with the soil definitions of the marsh mapping by the „Niedersächsisches Landesamt für Bodenforschung" was tried to be reached. Based on the soil analysis, the most outstanding qualities of tidal flat sediments found here and their relations are being discussed. Furthermore the boundary values for the classification are investigated.