The South Yellow Sea is a large superimposed basin of the Paleozoic, the Mesozoic and the Cenozoic, which can be divided into four structural layers with different characteristics: Structural layer I (Z-S), Structural layer 1] (D-T), Structural layer III (T3-E) and Structural layer IV (N-Q). The layer I is composed mainly of a suit of basin and platform faces of the lower Paleozoic by the data from outcrops and wells in the continental area. Based on the latest seismic profiles, it distributes widely and stably in the South Yellow Sea, with quite big thickness, but unclear about its tectonic characteristics. The layer II is made up of marine elastic rock and limestone of the upper Paleozoic to the Triassic, with compressive tectonic style predominantly. The residual strata and the structure of the layer, however, are of much variety from the south to the north of the basin, due to the great impact of Indosinian Movement and Yan Shanian Movement in the area. Due to the multi-cycle tectonic movement in the South Yellow Sea Basin, the characteristics of hydrocarbon reservoir and accumulation are different in different structural units. It is suggested that the northern depression would be the most prospective area for hydrocarbon since there are different kinds of hydrocarbon plays, such as old source-old reservoir, old source-young reservoir, and young source-young reservoir.
