Abstract: With the incremental exploration degrees of numerous domestic petroliferous basins, the discovery rate of giant oil-gas fields assumes decreasing trend on the whole. Petroleum energy becomes to be a focus influencing state security and national e-conomic development once again. In relatively matured basins, facing the situations of being poor quality of remained oil-gas re-sources and more complex conditions, how to correctly select areas or zones for petroleum prospecting and quicken to discover big and/or giant oil-gas field are key factors for realizing succession and transfer of China’s oil-gas production provinces in order to assure continuously incremental petroleum reserves and production rates. Taking Subei basin as a study example, it is found from its oil-gas distribution and exploration experiences that oil-gas showing probability from Grade III structures or previous drilling wells into faulted blocks can be well used for determination of enriched oil-gas in the exploratory area or not, hence proposing new method for quantitative prediction of big and/or giant oil-gas reservoir distribution and optimal selection of ex-ploratory target areas. Practices show that in Subei basin and Tarim basin, the predicted understandings using this method are closely matched to real prospecting results.

Key words: exploration, oil-gas field, oil-gas shows, Subei basin, Tarim basin