Abstract <p>For plane plastic deformation of an anisotropic medium, the stress state coefficient is determined. Graphs are constructed that characterize the effect of anisotropy on deformation amplification. The coefficient of anisotropy influence is given, showing how much the deformation force for an anisotropic medium is greater (or less) than for an isotropic one. It is shown that plane plastic deformation is possible only in a certain range of yield strength ratios.</p>