Abstract: Although Bohai Bay Basin has undergone through oil and gas exploration for over 40 years, its exploration is still in middle stage in general. On the basis of comprehensive analysis the exploration and research results onshore Bohai Bay Basin in 20th century, it is put forward that the following new ideas, i.e. Bohai Bay Basin might be a superimposed basin which was superimposed by Carboniferous-Permian coal-containing remained basin, Mesozoic rift basin and Cenozoic rift basin based on Paleozoic and middleupper Proterozoic craton; Dongshen large fault in Taihangshan Mountains controls the formation and distribution of oil-gas reservoirs distributed in the 4th member of Shahejie Formation , Kongdian Formation and pre-Tertiary; The geological structure of Tertiary oilgenerating sag controls the enrichment degree of oil and gas, and it is pointed out that it is key method for reserves increment to fined exploration for the Tertiary oil-generating sags, it is hope to explore the burial hill oil/gas reservoirs to ensure the bound increase of reserves.

Key words: oil/gas exploration, superimposed basin, Bohai Bay