Abstract: Nowadays,it becomes more and more difficult to explore for oil and gas. In order to discover new oil/gas fields, the relative theories of petroleum generation and principal concepts for oil/gas cxloration must be used,of which the author concluded in six aspects of topics. Combined these topics with the past practices and the characteristics in the areas of the East China,the new considerations in three aspects with seven new realms of oil/gas exploration in the areas have been proposed in this paper. The new conciderations in three aspects arc as follows; Ⅰ.The hydrocardons generated from multiple sources during polystages and oil/gas pools formed in various geological stages,and the later geological stage it is,the more favourable for the formation of oil/gas pools it will be. Ⅱ. The hydrocarbons generated and oil/gas pools formed in early geological stage or through the polystagcs,and the hydrocarbons have been scaled or absorbed by the formations after the diagen csis took place. Those oil/gas pools are favourable for petroleum development if the geological reworks have occurred. Ⅲ. New discoveries of oil/gas fields can be made in the highly explored areas by applying new petroleum theories,concepts and techniques. The seven new realms for oil/gas prospcctings are as: 1. The hydrocarbons derived from the Mcsozoic and Paleozoic marine sedimentary sequences; 2. shallow buried natural gas(including the Quaternary biogas) ;3. the middle and small sized basins in the areas of the East China; 4. the areas covered by volcanic rocks in the southeast provinces of China;5. the gas derived from coal measures;6. oil-bearing beds of tight sandstones of the Longtan Formation;7. the Meso-Cenozoic non-marine basins in the northern Jiangsu.