Abstract: Based on the ideas of a paper named the  function method to predict the remaining oil saturation distribution in water-flooding reservoir，considering the fluid characteristics in polymer flooding reservoir，such as polymer visco-elastic，shear thinning，non reached pore volume，permeability decline coefficient and other factors，on the basis of establishing the mobile plane saturation equation in polymer flooding，the changes of the viscosity of polymer solution and water permeability and the influence for polymer flooding function are analyzed.By using this method and numerical simulation software eclipse，the comparing calculation is carried out，the results show that the difference of polymer concentration distribution between them is small after polymer flooding，the value of the distribution of water saturation calculated with this method is relatively high，which shows that the tensile viscosity caused by the visco-elastic of polymer in the process of flooding acts.It is proved that the method can accurately reflect the flooding situation of the viscoelastic polymer in the formation.

Key words: visco-elastic polymer, remaining oil, φ function method, shear viscosity, tensile viscosity