Abstract: The Mauritania Coast Basin represents a classical passive margin basin created in response to the opening and drift of the Atlantic Ocean, which began in the Late Permian/Early Triassic times. According to the geological setting around, several oil-generative assemblages may bo exit in the study area, including Palaeozoic, Triassic, Jurassic and Cretaceous, but the Cretaceous dark mudstones are the main source rocks. The TOCs of Cretaceous source rocks are 1%-2%, which have been mature in the west of sea where water depth is 200 m. The Palaeogene and Neogene turbid sandstone is by far the most favourable target. Considering the petroleum geological characteristics, it is concluded that the pay zone is located in 200-1500 metres of water between shelf and slope.