Abstract: Various fault seals exist in Funing structure in Jinhu depression.It is discovered that fault activity has large im-pacts on sealing capacity through study on reservo irs of dif-ferent types and on fault blocks with no reservoirs.Two types of faults,early stage faults and long stage faults re-spectively,are identified according to the relations between time of fault being active and the critical time of oil-bear-ing system.Based on genetic mechanism study of fault seals ,it is believed that they have different properties and functions and control hydrocarbon accumulation and distri-bution of oil and water in fault block trap s.The early stage faults have good sealing capacity and layered reservoirs with multi oil and gas systems existing in fault block traps.While the long stage faults have variable sealing capacities,layered reservoirs with common oil and water system may exist,or no reservoirs exist.These understandings can be used to select exploration targets,to determine exploratory well types and to predi ct OWC.