Abstract: In order to study the effect of nitrogen (N) input of snowfall on the Deyeuxia angustisfolia wetland ecosystem in Sanjiang Plain,the snowfall,snow-pack,snow melting-water and leakage solution of soil (0～10 cm) were monitored from November 2006 to April 2007.The results show that the seasonality of the N concentration in snowfall is evident,and influenced by the manifold factors.The deposition of TIN,TON and TN in snowfall are 0.375,0.591 and 0.966 kg/hm² in winter,respectively.The snow-pack reservoir determines the N reservoir.The NH₄⁺-N and TON are the main body of TIN and TN in the snow melting-water,respectively,but the NO₃^--N and TIN lose more easily than NH₄⁺-N,TON,respectively.The interceptions of TIN,TON and TN are 1.53,0.1 and 1.63 kg/hm² by soil (0～10 cm) respectively.The nitrogen input of snow melting-water has directie ecological signification which stimulates growth of the plant and the microbe in soil.