In addition to the influence of deposition, physical properties of the clastic reservoirs can be seriesly transformed by diagenesis after deposition. Diagenesis are caused by external dynamic environment acting on the sediment. Because the external causes become operative through internal causes, The diagenetic evolution result are influenced inevitablly by the characteristics of the original sediments. Through the core description of 38 Wells and the observation of ordinary thin section, cast thin section and scanning electron microscope of more than 400 samples, and the analysis of physical properties, the oil bearing properties, the relationships between the factors, like reservoir lithology, grain size, matrix contents, bedding structure, bioturbation structure, and the diagenetic phenomenon, physical properties and oil content are studied in detail. The impact of sedimentary microfacies on diagenesis, reservoir properties and oil and gas are summarized. Composition of the reservoir have an important impact on reservoir diagenesis and physical properties, rock debris is relatively soft, easily compacted and dissolved, during shallow burial, porosity and permeability is increasing with the increasing of rock debris content. When buried deeper, porosity and permeability is decreasing with the rapid increases of the content of rock debris. The granularity of the reservoir also have important impact on the diagenesis and physical properties of the reservoir, generally speaking, porosity and permeability increase according to the increasing of particle size. The bedding types of reservoir also have an important impact on the diagenesis and petrophysical properties, sandstone with massive bedding, cross-bedding, parallel bedding, are with a good sorting and low matrix contents, and have grain support structure, which is conducive to the preservation of primary porosity, which supplied a good seepage conditions for the flow of underground acidic fluid and for the dissolution and alteration to reservoir in latter stage. In sandstone with wavy cross-bedding, in addition to there is not this condition, curved lamina inside sandstone increased the difficulties for underground fluid flow, so it is not conducive to the development of secondary porosity and for the oil and gas to enter. To discuss the controls of sedimentary microfacies to the reservoir properties, is mainly to discuss the control to its original petrophysical properties, during the burial and diagenetic evolution process of good sorted reservoir with high original of petrophysical properties, the resistance to the flow of formation fluids is very low, the reservoir space can completely disappear due to dense cementation, and can be preserved and improved due to the dissolution. Reservoirs with high mud content have a bad original petrophysical properties, and its resistance to the flow of formation fluids is big, especially it is difficult for oil and gas to enter the reservoir, so the reservoir space can hardly be improved and saved, and are mostly be destroyed.