The Campos Basin is a typical passive continental margin basin. Sedimentary rocks cover pre-rift (non-marine), syn-rift (transitional) and post-rift (marine) structural formations. The regional sealing rocks are saline formation. The pre-salt argillaceous shale and the post-salt Campos argillaceous shale act as the local sealing rock. The chief source rock is the black Lower Crataceous Logoa Feia lacustrine calcareous shale and the chief reservoir beds are the marine and continental sandstone and carbonate rock,ranging from the Barremian to Miocene in age. Upper Crataceous-Tertiary turbidites contain oil but Lower Crataceous Neocomian basalt is as the particular reservoir. Peak of hydrocarbon generation occurred during late Miocene time and the most important pathways of migration are through salt windows and along listric faults. The exploiting reservoirs are characteristic of low temperature, low API and low degree of sandstone cementation. The most oil fields known are sited within 10, area of the entire basin and the others fall in thecomplex geological areas or potential exploration areas.