Abstract: In north block of weizhou12-1 oilield, because of it’s serious heterogeneity and complex communication, oil produc- tion and recovery percent of reserves is low, and production stabilization is dificult with stable water injection. In order to improve it’s development effect and provide evidence for future adjustment, eight water injection projects was studied by numerical simulation technique .and by comparing, the optimized water injection program can improve recovery eficiency 3 percent than general water injec- tion program.