Field soil bores measurement and static C₂H₂ inhibition soil cores method was used to study N₂O emission in the loess soil profile and the factors affecting its production.Significant spatial variation and temporal variation of the nitrous oxide amount were found in the soil used.The temporal variation was correlated with the water supply (such as rainfall or irrigation), and N₂O peaks were occurred 3 days after water events.Both the control and fertilized plots have the same trend.August was the highest N₂O production month during the period.At the highest point the N₂O concentration in the fertilized plot was 2.5 times higher than that in the control plot.Meanwhile N₂O spatial variation in the profile followed the order: 10cm< 30cm< 150cm< 90cm< 60cm.Carbon was the limited factor that controled denitrification in the soil.When carbon was supplied, nitrate content and water became the limited factors.