In recent years, significant progresses have been obtained in the numerical procedures to describe microstructural evolutions during thermomechnical processes. The results allow to designers and metallurgists to study process changes without try and error and near realistic state, because computational models provide accuracy and enough ease. Many constitutive models are available for finite element modeling of plastic behavior of metals. However, application of most conventional these models is restricted by some parameters such as amount of strain, strain rate, temperature and in some cases microstructural evolutions. Nowadays, modeling of material behavior is very important to achieve accurate results of simulations. In this work, it was investigated microstructural evolutions of steel in hot deformation processes by using of definition of behavior models in ABAQUS finite element software. It is essential to learn computational plasticity concepts for definition of new behavior models. Then, it was studied several coupled micro and macrostructural behavior models. Finally, two sets of implicit and explicit structural equations were selected. These equations consist of changes of dislocation density, recrystallization fraction and grain size. These equations were defined for software by using of plasticity expressions and VUMAT object. In order to validate codes of program, a compression test was simulated and a sample was experimented at various temperatures and strain rates. In comparison, the results of simulation were agreed by experimental data. After validating of data, the hot rolling and forging were simulated to study microstructural parameters. At the end, the results were presented in the form of contours and diagrams.