The deep water district of Quasi-passive margin of the northern South China Sea is located in the place where the three major tectonic plates (Europe and Asia，India-Australia and the Pacific-the Philippines) interact.It has the basic properties and typical double-layer or three- layer structure and sedimentary character of the passive continental margin extensional rift and it has the basic geological conditions for reservoir forming like the adjacent shallow water area of the northern continental shelf.The geological conditions for oil and gas migration and accumulation in the deep-water basin of quasi-passive continental margin in northern South China Sea are similar to some typical passive continental margins in deep-water oil and gas rich regions of the world，but there are also some differences between them.The oil and gas migration and accumulation in northern South China Sea and the spatial distribution of gas hydrate have a paragenetic association in the vertical and a source supply relation on genesis，and the important oil and gas geological significance is that the appearance of shallow oil and gas and the submarine hydrate can indicate the existence of deep oil and gas reservoirs or serve as a pointing and tracing of deep petroleum exploration.Besides，the paragenetic association in space also broadens the fields of resource exploration and greatly expands the size and potential of its resources.
