Three single autotrophic denitrification biofilm reactors with artificial water are applied to study the influence of aeration treatments and carbon source on the N2O emission and N2O emission characteristics. The results show that the accumulative N2O emission amount and the conversion rate of N2O of reactor 1，2 and 3 in an operation cycle are 13.69，14.28，2.51 mg，and 1.36%，1.49%，0.236%，respectively. The comparative results of reator 1(continuous aeration) with reactor 2(intermittent aeration) show their accumulative N2O emission amounts and N2O conversion rates are similar. The accumulative N2O emission amount and the N2O conversion rate of reactor 3(organic carbon) are about 1/6 of those of reactor 2(without organic carbon). Aeration treatments have great influence on N2O emission characteristics，for reactor 1，the accumulative N2O emission amount increases persistently，the mean N2O emission rate and dissolved N2O concentration performance continue to decline after the first rise to the maximum. For reactor 2，N2O emissions are mainly in aeration period. The mean N2O emission rate and dissolved N2O concentration reduce after first increase. The N2O conversion rate of single autotrophic nitrogen removal process is lower than those of other biological denitrification processes.