The study of geological structure is very important for basin analysis and petroleum exploration. The Jizhong depression in Bohai Bay Basin is known to the world for its oil and gas fields on buried?hills, hence study in detail on the geological structure of the buried hills is key to improve petroleum exploration as well as further oil and gas discoveries. Based on analysis of hundreds of exploratory wells and systematic interpretation of 2D and 3D seismic data covering most areas of the whole Jizhong depression, the paper explored the stratigraphy and the fault system of the buried hills and revealed the general 3D structure of the buried-hills of Jizhong depression. The study shows in Jizhong depression there are six reginal unconformities which are bases of Changcheng, Cambrian, Carboniferous, Mesozoic, Paleogene and Neogene, accordingly the evolution of the Jizhong depression can be divided into seven tectonic stages. Faults cutting through the top unconformity of the buried hills can be grouped into three populations according to their strikes, such as the NE-, NW-, and EW-trending. Faults striking NE is the most developed population while NW striking faults developed mostly on the central?east part of the depression, and the E-W population is most seen at the transfer zones. Jizhong depression can be divided into north, middle and south three segments by two major transfer zones such as Xushui-Anxin fault and Hengshui fault, each one with its distinguished characteristics. From the genetic point of view, combining the stratigraphic combination, tectonic evolution, dominant faults and the present geometry of the buried-hills, we delineated 42 structural zones of the buried hills and discussed the evolutionary characteristics of the most important and representative buried hills in detail. The Pre-Mesozoic tectono-sedimentary evolution provided material basis for the development of the buried-hills, the compressional events during Indosinian movement and Early Yanshan movement has significantly modified the geometry of the stratigraphic units of the buried-hills, and the multiphase rifting since the Late Jurassic has controlled the generation-adjustment?molding process of the buried-hills in Jizhong depression.