An experimental study using a flow reactor and a numerical simulation with a detailed kinetic model have been performed to investigate the reaction mechanism of NO formation from pyrrole decomposition. The experiments have been conducted in a quartz flow reactor by using a mixture gas of pyrrole, O-2 and H2O with N-2 as a balance gas at atmospheric pressure and temperature range 800-1400 K. The detailed kinetic model consists of 505 elementary reactions and 89 chemical species, and the plug flow calculations have been carried out under same conditions as experiments. Model predictions are in reasonably good agreement with the experimental data for NO formation from pyrrole. Model predictions indicate that the main reaction pathways from pyrrole to HCN are direct reaction by pyrrole pyrolysis and pyrolysis reaction of HNCPROP (HN=CHACH=C=CH2) generated by ring scission reaction of pyrrole. HCN is converted to N-2 or NO via NCO and about 90% of nitrogen in pyrrole is transformed to N-2 or NO at the temperature of above 1400 K. The residence time has little influence on the reaction rate and the reaction rate largely depends on the reaction temperature. (C) 2011 Elsevier Ltd. All rights reserved.