Abstract: A new strategy for the smooth representation of three-dimensional contact surfaces is developed. This method can be applied to both regular and irregular meshes. In this method, the contact surfaces are modeled using bi-cubic parametric patches. These patches are defined only by using the coordinates and the normal vectors of the mesh nodes. The resulting surfaces are tangent plane continuous between adjacent patches and C1 continuous in the patches. A contact search algorithm is designed on the smooth contact surfaces to determine the contact points. Then the gaps and the contact forces are calculated using the penalty algorithm. The numerical examples demonstrate that the smooth contact surface ensures that the contact forces of the sliding nodes vary smoothly and provides an improvement in convergence behavior.