The retention of nitrate nitrogen(NO-3-N) and ammonia nitrogen(NH+4-N) with simulated tank in three riparian soil of Wenyu river was studied.The results were as follows: The retention of NO-3-N and NH+4-N of Populus cathayana-Quercus liaotungensis,Picea and Larix.principis-rupprechtii were 158.38,145.38,142.98 mg/kg respectively;Retention was mainly occurred in 0-10 cm layer;As the ratio of NH+4-N and NO-3-N was between 1.68~1.80,retention was relatively stable;Soil structure was closely related to retentio...