The paper deals with numerical considerations of buckling phenomena in steel strip during rolling and leveling of sheet metal. The self-equilibrating stress states due to residual strains caused by the rolling process are calculated by the spline function method. The developed numerical model provides an estimation of buckling critical loads and wave configuration. It is shown how the waves observed on the strip sliding over or lying on a rigid plane, so one can provide information about the distribution of the differences in the plastic strains over the width of the strip which leads to the buckled configuration. The spline function method proposed in this paper is simpler and more convenient than traditional finite element method in the buckling analysis.