Through analyzing the nitrogen concentration and the flow at hydrologic station of Huaxian County during 1996-2009

the characteristics of nitrogen pollution in Weihe River were discussed. The results showed that:(1) The annual mean concentration of ammonia

nitrite and nitrate decreased in the study years from 7.31 mg/L

0.74 mg/L and 2.25 mg/L during 1996-2000 to 6.88 mg/L

0.71 mg/L and 1.99 mg/L during 2001-2006

the average concentration of total nitrogen was also decreased.(2) The magnitude of the nitrogen average concentration in Weihe River was:ammonia >nitrite >nitrate.(3) The concentration of ammonia in the dry season was higher than that in wet and normal seasons

which was due to the decrease of flow and the increase of waste water in the Weihe River basin.(4) The point source pollution load proportion of the nitrogen pollution decreased and the non-point source pollution load proportion increased

and the general trend was that the non-point source pollution load proportion increased strikingly from 1996 to 2006.