Abstract: Oil and condensate samples, as well as extracts of Upper and Middle Jurassic Source rocks in the South Viking Graben were analyzed for geochemistry and isotopic composition in order to find out the characteristics of hydrocarbons and the genetic relationships between hydrocarbon and source rocks. Seven hydrocarbon families are linked to three source horizons, they are, the mudstones of Upper Draupne Formation; the mudstone of Lower Draupne Formation, and the carbonaceous shale and coals of the Middle Jurassic Hugin and Sleipner Formation. The Upper Jurassic Draupne Formation is the principle source rock. Available data in this study indicate that 84% of recoverable oil resources came from the Upper Jurassic Draupne Formation.