In this paper the parameter identification using dislocation density based material model is studied. The model is rate-dependent and includes isotropic strainhardening/ softening as well as kinematic hardening. The model is implemented as a part of the custom toolbox for parameter identification (described in the accompanying paper) using Matlab®. A general stress-strain algorithm is used in the calculations, so the same logic can also be used when implementing the material models into a finite element code. The stressupdate algorithm of rate-dependent plasticity is chosen in the form that has the yield surface for which a so-called consistency condition exists. The amount of plasticity in a strain increment is determined by the consistency condition, whereas the internal variables history and yield stress depend on the plastic strain-rate. The paper focuses on the use of physically based material models. The dislocation density concept links the macroscopic stresses and strains to the underlying micro-structural processes of plastic deformation. The material models define evolution equations for the densities of mobile, immobile locked and immobile recoverable dislocations. The physical significance of the model parameters is highlighted. The developed toolbox is used to determine material parameters of a high-strength steel for a chosen dislocation density model fitted to the constant amplitude fully reversed strain controlled cyclic test curves. Parameter sensitivity is briefly discussed.