Abstract: This paper discusses measures to improve retaining rate of injected water in reservoir in late stage of oilfield development through analyzing the relationships between retaining rate of injected water and the ratio of total oil produced to OOIP, pressure, and fluid productivity index. In order to improve retaining rate of injected water in an oilfield or a block, appropriate measures should be selected according to the characteristics of production in different development stages and poroperm characteristics of oil layers. These measures include enhancement water injection, overall correction of profile, plugging layers with high water saturation and shutting down stripper wells with high water cut. They can be used to maintain reservoir pressure in a development unit and to improve development effects of oilfields.