Abstract: Based on percolation theory and oil/water two phase 3D network pore model,with the consideration of the rheological properties of the polymer，the adsorption and the depleted layer effect，a oil/polymer pore model is established.The validity of network model is testified by the comparison of simulation and experiment of polymer-oil relative permeability steady flooding.Then the effect of pore-throat ratio,adsorption，rheological properties and the depleted layer effect are studied by means of microscopic simulation，which shows that residual oil saturation and water relative permeability are larger as pore-throat ratio becomes larger，the water relative permeability smaller as the power index become larger.The thickness of depleted layer is not sensitive to oil relative permeability while water relative permeability becomes larger as it increases.The less the adsorption is，the less residual oil saturation is produced.Compared to other idea models ，the 3D network model is more veritable for studying oil and polymer flow mechanisms.

Key words: Network Pore Model, Polymer Flooding, Effective Viscosity, Relative Permeability Curve, Influencing Factor