Abstract: NO_x emission characteristics of Shanxi anthracite were tested in a 20 kW one-dimensional self-sustaining furnace system under different air-staged combustion conditions. Results show that the self-built test system helps to realize the self-sustaining combustion of pulverized coal and is able to effectively simulate the whole process from pulverized coal flow to coal combustion and NO_x formation in the furnace. Under single-staged combustion conditions, the NO_x reduction efficiency increases with the deepening of air staging, and the maximum reduction efficiency may get up to 51.7%. With the deepening of air staging, the best postion of burnout air nozzles move upward. The NO_x reduction efficiency in multi-air-staged combustion condition is greatly higher than the single-air-staged condition by appropriately arranging the burnout air nozzles and reasonably selecting the burnout air ratio, which may reach 60%.