Abstract: This paper presents 6 ways of polymer injection,and studies the sensitivity of injection way on polymer water flooding results for the conditions of different heterogeneity,different anisotropy and different polymer injection time with the aid of three-dimension two-phase four-component polymer water flooding simulator.In general,the reservoir with the poor waterflooding effectiveness is sensitive to polymer injection way.For longitudinal intraformational heterogeneous reservoir,the normal sedimentary sequence is more sensitive than reverse sedimentary sequence to injection way;for the horizontal heterogeneous reservoir,the reservoir of main streamline with higher permeability is more sensitive than that with lower permeability;early polymer injection is more sensitive than late injection.