Abstract: Water injection is one of the major measures to keep formation pressure and improve oil recovery. But water sensitive damage cauSed by waterflood is also one of the major reasons causing the descending of injectors’ injectivity for the sandy formation with sensitive minerals. A new gradient water injection technology of descending step by step the injection water salinity to the formation water salinity was developed based on the characteristics of with higher sensitive minerals in formation of Rongxingtun Oilfield. At the same time, in order to enhance waterflood effect and be convenient to implement in oilfield, clay inhibitors were put into injected water. The experiment in lab and application in oilfield showed that the new technology had greater adaptability than other routine measures and had produced good stimulation effects.