Abstract: In water flood development oilfield,contradiction among different layers and planes is getting increasingly serious,e specially during the late stage of oil field development, when reservoir heterogeneity becomes severe and water flooding imbalanced.Therefore,it is important to have reasonable injection rate so as to improve water flood effectiveness. In order to inject water into poor areas and uncontrolled areas of well pattern,flow direction should be changed.While considering the differential physical properties and the contradiction among different layers and planes after longtime water flood development and adjustment,by means of numerical simulation,reasonable injection allocation in vertical direction was determined.After that,by making oil wells as the center,plane injection allocation was ascertained according to balanced injection and production rate.In the end,injection flow rate on each layer could be confirmed by the vertical injection allocation and plane injec- tion allocation together.