Abstract: The effects of exogenous nitrogen on N₂O production processes in the soils of un-restoration wetland (R₀), restoration wetland since 2007 (R₂₀₀₇) and restoration wetland since 2002 (R₂₀₀₂) of the Yellow River estuary were studied, and the contributions of different processes in N₂O production were determined. Results showed that the N₂O production of restoration wetland soils (R₂₀₀₂ and R₂₀₀₇) with NO₃^--N addition was much higher than that with NH₄⁺-N addition, but both NH₄⁺-N and NO₃^--N additions demonstrated inhibition on the N₂O production of soils in R₀. Although the effect of NO₃^--N addition on the total N₂O production of topsoil in R₂₀₀₂ was significantly higher than those in R₂₀₀₇, the values in R₂₀₀₂ and R₂₀₀₇ were greatly increased with increasing NO₃^--N addition. The denitrification and nitrifier denitrification processes in restoration wetland soils (R₂₀₀₂ and R₂₀₀₇) were greatly affected by NO₃^--N addition, but no significant influence on the non-biological processes of soil in R₀ was observed. Although NH₄⁺-N addition did not produce significant effects on the total N₂O production of wetland soils, the nitrifier denitrification process in R₀ soil, the nitrification process in R₂₀₀₇ soil and the non-biological process in R₂₀₀₂ soil were generally stimulated. In R₀ and R₂₀₀₂ soils, the N₂O produced by non-biological processes was generally eleva-ted with NH₄⁺-N addition, while with NO₃^--N addition, the non-biological processes generating N₂O in R₀, R₂₀₀₂ and R₂₀₀₇ soils were generally inhibited, which was closely correlated with the regulation of soil pH caused by the import of exogenous nitrogen. This study found that the enrichment of NO₃^--N greatly enhanced the total N₂O production of wetland soils and significantly altered the original contribution patterns of biological and non-biological processes to N₂O production. Thus, special attention should be paid on the influences of nutrient import (particularly NO₃^--N enrichment) induced by ecological restoration project on N₂O production of wetland soils.