Abstract: A large amount of the borehole data has been acquired in recent years with the seismic geological monitoring program in the urban area of Weifang. The Quaternary of the area could be divided into 23 geological layers and more sub-layers. Isopach maps for the Quaternary system and its members and other kinds of maps and diagrams are made by the authors to reveal the spatial distribution patterns of the Quaternary sediments. Upon the basis, preliminary analysis and discussion are provided in the paper on the main control factors over the Quaternary deposits in the urban area of Weifang.