采用实测咸度资料对新安江建库和治江围垦前后杭州段江水咸度的变化进行了分析。认为新安江建库后枯水迳流的增加和围垦治江潮差的增大是影响咸水入侵的重要因素，采用一维咸水入侵数学模型定量地分析了两者各自对咸水入侵的影响结果，分析与实测的结果基本一致。 The measured salinity data were used to analyze the changes of salinity of Hangzhou section of Xin’anjiang reservoir before and after the reclamation. It is considered that the increase of dry scum flow and the increase of tidal range in reclamation after reclamation in Xin’anjiang River basin are important factors affecting the intrusion of saline water. One-dimensional saline intrusion mathematical model was used to quantitatively analyze the influence of both on saltwater intrusion Results, the analysis and the measured results are basically the same.