The band structure of ZnS calculated from empirical pseudopotential method is fitted by use of polynomials. The density of state and scattering rates are also calculated from these polynomials. Based on these results, electric transport process in ZnS-type thin film electroluminescent devices is simulated through Monte Carlo method. By comparison with other methods, the calculation based on this m odel is as fast as nonparabolic model and as accurate as full band model. Furthe rmore, the influence of band model on simulation result is also investigated. We show that the dispersion relations and density of state are all important in si mulation.