Abstract: Influence of 3 kind of water on viscosity of polymer solution before and after shearing in JZ 9-3 Oilfield was studied by experiment and the result shows that under the same concentration the polymer solution prepared by mixed-water of sewage and water had the highest viscosity, followed by polymer solution prepared by sewage and solution prepared by water source has the lowest viscosity.The viscosity retention ratio of polymer solution sheared by WARING stirrer indicates that the highest viscosity retention ratio is polymer solution prepared by sewage,and when the sewage concentration is higher than 1 000 mg/L, viscosity retention ratio is about 90%.The lowest viscosity retention ratio is polymer solution prepared by water,and viscosity retention ratio is about 55%.