Abstract: Varies data including thin section analysis, scanning electron microscope, image analysis, intrusive mercury, X-ray diffraction, organic matter evolution and physical property variation are used in diagenesis study of the Wendong deep low permeability reservoir. Five typical diagenetic facies patterns are established based on study of the types of diagenesis, diagenetic evolution history, pore evolution sequence and the relationship between diagenesis and micro sedimentary facies, and the plane distribution of diagenetic facies patterns is also studied. It can be used for reference in study of diagenesis and diagenetic facies patterns of deep low permeability overpressured oil reservoirs.