The behavior of developer in a two component magnetic brush system is studied by numerical analysis using the distinct element method which is a category in the particles method. The hybrid model which contains both of the softsphere model and the hard sphere model is proposed. The volume of the numerical calculation is reduced by the hybrid model. The electromagnetic forces and the collisional forces which are derived from the hybrid model are introduced to the force equations. To solve these equations a carrier and a toner behavior are analyzed. The spike phenomena of the carrier particles, the developments to the latent images and their quantitative analysis are obtained by solving the force equations numerically. We obtain the dependence of developed toner mass upon some device parameter using the hybrid model.