Abstract: A series of experiments were conducted in a multiplefunctional combustion test bed with several kinds of biomass as reburning fuel to reduce NOx. The character and experimental parameters are emphasized to examine the influences on NOx reduction. The results show that biomass could get about 55% to 70% NOx reduction. Within a certain range of the parameters tested, NOx reduction increases with the increasing temperature of reburning zone and initial concentration of NO, and with decreasing excess air ratio and diameter of fuel particle. Under the same test conditions, cornstalk gets the highest NOx reduction and wheat straw, peanut shell，wood ship follow in turn.