Denitrification from soils is the main pathway of gaseous loss for nitrogen in the catchments.We measured the denitrification rate from the top-soil in Wuchuan catchment by using the acetylene inhibition technique.The result of this experiment indicated that denitrification of the soil had the temporal and spatial variance.The rate of denitrification that occurred in uplands of the catchment was higher than any other places,and denitrification was enhanced when there were many rains and when the soil temperature was high.The flux of denitrification was mostly related with fertilization,soil moisture and air temperature.Air temperature was top-dressed affected denitrification significantly.The gaseous N loss rate through denitrification represent about 16% of the fertilizer applied in the catchment scale.