Mechanism of AlN combustion synthesis was studied by DSC analysis and “quenching” experiment of combustion wave. In preheating region, Al powder melted at 660 ℃ and became spherical because of surface tension. In reaction region, Al volatilized rapidly at 1 000 ℃ and Al vapor reacted with N_2 to form AlN, which nucleated and grew on the surface of AlN formed precedently as a diluent. Based on the experiment analysis, kinetics equations and modeling were established. Analysis showed the dramatic effect of temperature, aluminum particle size and nitrogen pressure on the reaction speed. Mechanism of AlN combustion synthesis was studied by DSC analysis and “quenching” experiment of combustion wave. In preheating region, Al powder melted at 660 ° C as spherical because of surface tension. vaporized with N_2 to form AlN, which nucleated and grew on the surface of AlN formed precedently as a diluent. Based on the experiment analysis, kinetics equations and modeling were established. Analysis showed the dramatic effect of temperature, aluminum particle size and nitrogen pressure on the reaction speed.