The multiscale mechanical behaviors of Ferrite-Pearlite steel were predicted using Numerical Material Testing (NMT) based on the finite element method. The microstructure of Ferrite-Pearlite steel is regarded as a two-component aggregate of Ferrite crystal grains and Pearlite colonies. In the NMT, the macroscopic stress-strain curve and the deformation state of the microstructure were examined by means of a two-scale finite element analysis method based on the framework of the mathematical homogenization theory. For the NMT of Ferrite-Pearlite steel, constitutive models for Ferrite crystal grains and Pealite colonies were prepared to describe the anisotropic mechanical behavior at the micro-scale.