Paper presents new idea of modelling the magnetic hysteresis in the Jiles-Atherton model. Presented approach considers physical principles of magnetisation process and main assumptions of Jiles-Atherton model. As a result modified differential equation stating the model was proposed. This equation was verified on the base of magnetic hysteresis loops of non grain oriented electrical steel. Presented results indicate, that proposed approach to modelling the magnetic hysteresis loops well correspond with results of experimental measurements.