This paper presents an experimental investigation of the influence of combustion-air staging on the formation and reduction of NO and N20 from coal combustion, carried out in a 6.2-m-tall and 0.161-m i.d. circulating fluidized-bed (CFB) combustor. The main operating parameters examined were secondary air ratio and air staging position. It was found that NO generated in the primary combustion zone could be effectively reduced in the secondary combustion zone. The effect of combustion-air staging on the N20 emissions was found to be relatively small. The axial concentration profile of N20 along the CFB furnace, however, could be significantly influenced by the air staging position. Detailed analyses were made of the chemistry of NO and N20 formation and reduction under combustion-air staging conditions. It was revealed that the axial distribution of NO and N20 along the CFB furnace could be the combined effect of initial distribution of intermediate coal-N, coal combustion performance and furnace hydrodynamics. Unlike traditional approaches, in which exhaust gases only are discussed, this paper for the first time introduces analyses of axial profiles of NO and N20 in a CFB furnace under combustion-air staging conditions, which should provide a better understanding of the influence of combustion-air staging on NO and N20 formation and reduction in a CFB furnace.