Shoe traction has a great influence on running performance. Materials used in shoe soles have visco-elastic properties with strain-rate dependency. In previous studies concerning shoe traction, "Coloumb's friction theory" of contact between two rigid bodies has been used, however, this application has not been proper. In this study, the assumption that the appearance of slipping depends upon the stored energy in the sole/surface interface is proposed. The numerical estimation method of shoe traction, based on FEM considering the visco-elastic properties of shoes materials, is developed. The appropriateness of the numerical model is discussed by comparing experimental results. Using this model, the effects on traction of the constitutional parameters, midsole hardness, and outersole density are quantified. Furthermore, the application of the model to traction on wet surface is discussed.