In recent years,because of the dramatic changes in the upstream runoff of the Yangtze estuary,sea tide and estuarine marine environment,and more engineering constructions in the Yangtze River estuaries and along the coast,specially the constructions of the Yangtze estuary deepwater channel regulation project may cause some changes in the tidal estuary.Based on the analysis of the Yangtze estuary deepwater channel project construction before and after the long-time series of 11 tidal station data,we get to know the tide variation characteristics of Yangtze estuary in recent period and realize that the tidal characteristics out of the estuary is mainly affected by the outer tidal changes,and that in the mouth is mainly affected by the deepwater channel regulation project and surrounding engineering construction.