Nitric oxide (NO) reduction through coal, biomass and their blend reburning is conducted on a drop tube furnace experimental system and it is proved to be feasible of using the coal-biomass blend as the reburning fuel. For a high NO reduction efficiency, the excess air ratio in the reburning zone should be less than 0.9 and the reaction temperature is required to be higher than 1373K. 50-60% of the biomass percentage in the blend is enough for an acceptable efficiency. At the same time, for a thorough NO reduction process, the reburning fuel fraction and the residence time in the reburning zone must be guaranteed about 20% and 0.6-0.8s, respectively. Also, when the initial NO concentration is excess 600ppm, the efficiency is varied little at different NO concentrations.