The three dimensional finite element models of rod have been built on the basis of thermo-mechanical coupled elastic-plastic FEM in order that the rolling process of No.5 pass is simulated accurately. The distributed rule of friction is calculated and discussed with variable initial rolling temperature, diameters of rollers, reduction in pass and rolling speeds. The results show that the fore sliding region, adhesive region and back sliding region are existent on the surface of rolling material. Furthermore, friction force is calculated by using numerical simulation method and it is a new approach in studying friction. The analysis of friction force is available for reference to optimize processing parameters in the rolling process.