Abstract: As an ecological ecotone between land and water area,nitrification-denitrification is two important processes of nitrogen cycle in riparian zone.The potential and influencing factors of nitrification and denitrification in riparian zone during flooding period and dry period are explored.It provides a certain scientific basis for nitrogen pollution control of water body.In this study,the riparian zone of Xia jiasi was selected as the research object,the soil samples of riparian zone were collected in flooding period and dry period respectively,and the nitrification and denitrification intensity of riparian zone in dry and wet environment were measured by indoor culture experiment.The results show that:（1） the maximum content of EC,pH,SOC,NH₄⁺-N、NO₃^--N and TN appear in surface soil no matter during the flooding period or during the drying period.（2） the maximum nitrification rate and nitrification activity of all layers of soil in riparian zone during flooding period were（1.81,0.44,0.83）mg/（kg·d）,（86.18,22.38,40.38）%.The maximum nitrification rate and nitrification activity of each layer during the drying period were（3.00,2.05,0.48）mg/（kg·d）,（138.97,96.92,24.45）%.The maximum nitrification potential of the riparian zone appeared in the topsoil,and the average nitrification potential in the dry period was higher than that in the flooding period.（3） the denitrification rate decreased with the increase of soil depth,and the denitrification rate of topsoil reached the maximum,which was（69.98,63.91）mg/（kg·d）,respectively.The average denitrification rate of riparian zone in dry period24.23 mg/（kg·d）was higher than that in flooding period24.02 mg/（kg·d）.The denitrification activity in flooding period reached the maximum value of 99.07%in 10 days after culture,and it reached up to 101.91%in 6 days after culture in dry period.（4） the differences in nitrification potential and denitrification potential in flooding and dry period were related to soil environmental factors.The nitrification potential in flooded period was positively correlated with SOC,NH₄⁺-N and pH content,and nitrification potential in dry period was positively correlated with TN.There was a significant positive correlation between denitrification potential and SOC,NH₄⁺-N content in dry period.It was found that carbon source and nitrogen were the main factors affecting nitrification and denitrification potential in riparian zone.