Abstract: Sedimentation in continental basins is generally controlled by tectonism and palaeocli-mates.The present paper focuses on the sedimentary environments of the Dongying For-mation in the Xiaowa oil field on the basis of the analysis of stratigraphic,palaeontological, sedimentary and geochemical data.The sediments are mainly derived from the central up-lift in the northeast.The palaeoclimates are semiarid and semihumid temperate climates, and the water media indicate weakly reduced freshwater littoral and shallow lacustrine en-vironments.The abundant weathering products were differentiated and transported by rivers into lakes to form the deltaic sedimentary bodies in the study area.