Abstract: By analyzing the characters of structural and oil-gas distribution in the south beach area of Dagang Oilfield, the authors believe that fault is a chief controlling factor of oil-gas distribution, and generalizes macroscopic and microcosmic regularities of oil-gas distribution. Hydrocarbon is mainly distributed in the intersections of major faults that were active during the formations of Shahejie and Dongying strata.Therefore,oil in the south beach area mainly exists in Palaeogene sediments,and favorable exploration targets are probably the 1st member of Dongying Formation and 1st and 2nd members of Shahejie Formation.