Abstract: The progress in seismic acquisition technology for marine strata has made the advanced study on marine Mesozoic-Palaeozoic strata possible in the South Yellow Sea Basin. Based on the new seismic data and other data of geology, geophysics and geochemistry collected from the South Yellow Sea Basin and surrounding regions, we discussed in this paper the petroleum geologic characteristics of the South Yellow Sea Basin, and prospecting targets for marine strata were selected. The study results suggested that marine Mesozoic-Palaeozoic strata have a steady distribution in the study area with thick residual deposits including 4 suites of source rocks, 2 categories of reservoirs, 4 suites of mudstone cap rocks, which form favorable source-reservoir-cap assemblages for the formation of hydrocarbon accumulations. There are two good exploration prospect targets:the middle and western part of the Laoshan fault-uplifting belt where targets are available in the lower marine structural layer, and the Qingdao depression and the western part of Wunansha folded belt where targets occur in the upper marine structural layer and the middle and western part of Laoshan fault-uprising belt are the best targets for exploration.