Abstract: In order to know whether the low permeability oil layer can be done associated polymer oil displacement or not, the indoor physical simulation test has be done to 9 sample cores whose permeability are less than 100×10^-3μm². The result shows there are certain effect in low permeability reservoir, and define the lowest permeability of reservoir can be done associated polymer oil displacement is 40×10^-3μm², and in the same permeability, the larger the injection of associated polymer, the more the oil recovery. These conclusions provide important references for doing associated polymer oil displacement in low permeability reservoirs.