In Neogene meandering stream channel sand bodies in Jiyang depression，the petroleum usually concentrates in a given pay bed，and only several given sand bodies are filled with petroleum in the given pay bed.The reasons causing these phenomena are discussed in this paper.Firstly，the differentia of fault activity and reservoir-cap assemblage result in the differential distribution of petroleum in meandering stream channel sandstone in different pay beds of different prolific zones.Secondly，the contact relationship between channel sand bodies and transforming faults and structural settings have caused that only several given sand bodies are selectively filled with petroleum in a given pay bed of a given prolific zone.Thirdly，the reservoir characteristics of channel sandstone also influence the selective injection of petroleum into channel sand bodies.Generally，under the same reservoir-forming conditions，the major river channel sand bodies have advantages in reservoir quality and are more easily to concentrate petroleum.The analyses of the reasons of petroleum selective injection have great significance in the zone and play selection，as well as practical well location in the process of petroleum exploration.