Abstract: Simulated the reservoir conditions(47.5℃) of the PuBei reservior G2 block in Daqing oil field，the resistance coefficient and residual resistance coefficient of both hydrophobic associating polymer and the common polymer with middle relative molecular mass are measured and the oil displacement experiments using the three layers of heterogeneity of artificial core were carried out. Then the results of the experiment were analyzed. The experimental results show that under the condition of different concentrations and different viscosity, the resistance coefficient and residual resistance coefficient of hydrophobic associating polymer are both higher than the common one obviously. Advanced treated wastewater., whose salinity is 5366 mg/L, was used for preparation of polymer solution. The oil displacement efficiency in the three layers of synthetic of heterogeneous cores shows that the oil recovery enhanced by 700mg/L of hydrophobic associating polymer is 16.11%, which is 3.57% higher than by 1200mg/L of common polymer on the basis of water drive recovery factor. Then hydrophobic associating polymer has a better oil displacement effect for the low permeability core and is more suitable for the polymer flooding in PuBei reservior G2 block.