Abstract: The viscoelasticity effect of polymer solution in the seepage process has a great influence on its apparent viscosity, which is why we should consider the viscoelasticity effect in the mobility designing for polymer flooding. Depending on the idea of mobility control and the concept of effective viscosity, this paper analyses the influence of the viscoelasticity effect on the minimum polymer solution mass concentration. The results shows that when the viscoelasticity effect is considered, there will be a critical point in the curve of the minimum of the polymer solution mass concentration with the increasing of shear rate, which obviously differs from the situation where the viscoelasticity effect is not considered. Meanwhile, with the increasing of the relaxation time and at the same shear rate, the minimum mass concentration as required is decreasing, the whole curve moves down, and the longer the relaxation time, the earlier the time when the critical point appears, which means the enhancing of the elasticity effect can reduce the requirements of mobility designing on the polymer solution mass concentration