In this work the magnetic flux distribution in the grain-oriented steel core transformer is investigated with the finite element method. A mathematical model (Model II) is obtained for the reluctivity tensor. The model, optimized by means of experimental values of the B-H curve, predicts different directions of the magnetization field, not just along the rolling and transverse directions of the material. The results are the flux maps, as well as the reactance values and the electrodynamic forces on the windings. These results, obtained by means of the isotropic model and the anisotropic first model , are compared with the experimental ones.