Abstract: A kind of profile modification technology using weak gel of non-ion polymer, named PMN/BW, applicable in high temperature and high salt oil-field, some test results about the property of the gel system of PMN/BW in laboratory are discussed, including the property of gelent solution, the change curve of viscosity, the resistance to salt and the tolerance to heat after gelling and the ability to resist the cut etc.Also the application results in Huabei oil-field of injection well Gao 30-49(114℃) in Gao 30 zone are discussed.The local results show that both the profile of the injection well is modified, whose main drink layer is controlled, and latency layer is started up, and the production well group around achieved an evidence result of oil increasing, whose oil production is increased by 1462 tons during 8 mounths.