Abstract: Polymer flooding technology is applicable for non-homogeneous medium and heavy oil reservoir. It is simpler compared with other EOR technologies, and more suitable for HSE requirements in offshore oilfield. According to the reservoir features and polymer structure property, combining with offshore platform features, a salt resisting polymer has developed which has high viscosifying action, better shearing resistance, fluidity and displacement characteristics. It was the first time to use polymer 3640D to do pilot test of single well polymer flooding in offshore oilfield, and obtained remarkable effect of increased oil and decreased water. The multiple wells polymer flooding test also increased oil production. It is indicated that using polymer 3640D as an oil displacement agent is feasible in Jingzhou 9-3 Oilfield and it had broad application prospects in the polymer flooding technology of similar offshore oilfield.