Flue-gas recycling combustion of a sub-bituminous coal and its rapid pyrolysis char at 1120K has been simulated experimentally in a bubbling fluidized-bed. O 2 , CO 2 and H 2 O, and NO or N 2 O were pre-mixed and fed into the bed together with coal/char particles with the O 2 concentration in the exit gas maintained at 3.5vol%. Increasing the inlet O 2 concentration, thus increasing the O 2 consumption rate and decreasing the flue-gas recycling ratio, caused the once-through conversion of fuel-bound nitrogen into N 2 O to decrease while the conversion to NO to remain unchanged. The in-bed reductions of NO and N 2 O were both first order with respect to the respective nitrogen oxide, with the rate constants to increase linearly with the rate of O 2 consumption in the bed and thus also with that of char/volatiles consumption. This finding, which indicated linear increase in the concentrations of reactive species involved in NO/N 2 O reduction with the rate of O 2 consumption, enabled consideration that the homogeneous and heterogeneous reduction rates of NO and N 2 O were proportional to the consumption rates of O 2 by the volatiles and char, respectively. The rate analysis of the kinetic data revealed the relative importance of burning volatiles and char as the agents for the reduction of NO and N 2 O. While the reduction in the gas phase was fully responsible for the NO-to-N 2 O conversion, the reactions over the char surface governed the NO-to-N 2 reduction. The volatiles and char had comparable contributions to the reduction of N 2 O to N 2 . The NO-to-N 2 and N 2 O-to-N 2 reductions over the char surface were, respectively, accelerated and decelerated by increasing the H 2 O concentration.