The coastal wetland which is located in the marine-terrestrial interlaced zone，has high ecological values.In recent hundred years，human activities have profoundly changed the N2O flux of coastal wetlands.In order to explore the effect of exogenous nitrogen on potential of N2O reduction in the coastal wetlands，the variation of N2O reduction rate was studied in reed wetland in Chongming Island，Yangtze River Estuary and reclaimed paddy field with different reclamation years (19，27，51 and 86 years) after adding different exogenous nitrogen.The results showed that the reduction rate of N2O in the reed wetland soil was the highest under the condition of no nitrogen addition with value of 36.6 μg·g-1·d-1，which was 103% higher than that in the paddy field with 19 reclamation years.Under the condition of adding nitrate nitrogen，the N2O reduction rate of the paddy field with 86 reclamation years was the highest，which was 3.9 times that of the paddy field with 19 reclamation years.Under the condition of ammonium nitrogen and nitrate nitrogen addition，the annual growth of N2O reduction rate were 0.37 and 0.69 μg·g-1·d-1·yr-1，respectively，which were 140% and 343% higher than that in no nitrogen treatment.For the same soil，the effect of exogenous nitrogen input on N2O reduction rate was different.The N2O reduction rate of reed wetland soil under ammonium nitrogen addition was 32% lower than that of no nitrogen treatment，whereas the rate of the paddy field with 86 reclamation years soil increased by 91% under nitrate nitrogen addition.The correlation analysis showed that N2O reduction rate was positively correlated with soil organic carbon and total nitrogen，but negatively correlated with soil conductivity and sulfate.Therefore，in the rice production in the reclamation area，different forms of nitrogen fertilizer application have an important effect on N2O reduction process of coastal paddy soils.