Abstract: Based on the tides，salinity data of Yangtze River Estuary in dry season over years and the data from September to early November of 2022，the river discharge of Datong and Xuliujing Stations during the same period，we analyze the characteristics of saltwater intrusion in the north branch in 2022 and their differences with previous years.Combined with the river discharge and extreme weather conditions，we discuss the factors of influence，range of influence and diffusion path.The analysis showed that the start time of saltwater intrusion in north branch of Yangtze River Estuary in 2022 was significantly earlier than that in previous years，the salinity significantly increased.The salinity was negatively correlated with the river discharge.The intrusion was sensitive to typhoons and the north wind of cold waves which affect the Yangtze River Estuary.A phenomenon of saltwater intrusion from north branch superimposing with major saltwater attack through the south branch appeared.Saltwater intrusion showed periodic trends similar to tides，whose salinity was positively correlated with tidal dynamics.The intrusion could affect the water between Baimao and Chenhang Reservoir along the right bank of the south branch of Yangtze River Estuary.