Abstract: The particle model was employed to study the coal devolatilization, the release of volatile fuel-nitrogen, formation of HCN and the subsequent conversion to NO during the devolatilization. The finite volume numerical scheme was used to solve the equations of mass, chemical species, momentum and heat transfer conservation about the coal particle. The two competing reactions model was used to describe the devolatilization process, the results from the numerical simulations were compared and also verified with the experimental data. The simulating results show that the furnace temperature, particle diameter and the environmental oxygen concentration have influences on the release of volatile fuel nitrogen and the subsequent conversion to NO.