Porosity and permeability of sandstone near the sandstone-mudstone boundary is affected by the stacking pattern of sandstone and mudstone. At shallow buried depths (<2500 m), the reservoir quality near the boundary is superior to the inner part of the reservoir. At deep buried depths, the stacking pattern, mudstone thickness, and the ratio of sandstone in the strata heavily affect the physical properties of the reservoir near the boundary. When mudstone is interbedded with sandstone and the sandstone is very thin with a low ratio, the sandstone has very poor physical properties, while its thickness increases to some extent (becoming medium thick). The physical properties are getting poorer from the interior of the sandstone to the sandstone-mudstone boundary. There exists a physical property transition zone whose thickness is 1/4~1/5 that of the sandstone. When mudstone at the top while sandstone at the bottom, or sandstone at the top while mudstone at the bottom, there is a physical transition zone only on the side of the contact with the mudstone. When sandstone and mudstone are alternated with almost the same thickness, the reservoir quality near the boundary is still inferior to the inner part of the reservoir, and with the decrease of the thickness and ratio of sandstone, quality of the sandstones is getting poorer. When the sandstone is interbedded with thin mudstone, physical properties of the reservoir around the boundary tend to be the same as that of the inner part of the reservoir, so the physical transition zone disappears. This phenomenon is closely connected with the diagenesis of mudstone. Fluids discharging from mudstone at shallow or medium depths are low in salinity and rich in organic acids. The dissolution near the boundary is more active than that in the inner part of the reservoir at shallow buried depths, whereas at deep buried depths, K , Na , Ca 2 , Mg 2 , Fe 3 , Si 4 and so on discharging from the mudstone are precipitated in most cases, so the cementation near the boundary is stronger than that in the interior, especially when the mudstone has greater thickness.