Tidal asymmetry exerts an influence on nearshore material transportation and geomorphic evolution.Based on the Delft 3D FM,a two-dimensional hydrodynamic model is employed to establish the tidal movement simulations of Lingding Bay under the conditions of 1 970 s,2 010 s and the 2016 governing guideline shoreline.The response of tidal asymmetry to the seaward advancement of the shoreline in this area is analyzed by combining the reconciliation analysis and the skewness calculation method.Furthermore,the mechanism underlying tidal asymmetry change is examined by analyzing the contribution of different tidal constituent combinations.The research results show that the tidal height asymmetry between spring and neap tides in Lingding Bay varies.The seaward advance of the shoreline strengthens the flood tide dominance in tidal asymmetry.The seaward extension of the shoreline increases the tidal amplitude of the shallow water components while reducing the amplitude of the astronomical components,concurrently accelerating the tidal wave propagation speed.The contribution of the astronomical tidal components to tidal asymmetry gradually decreases upstream,whereas the contribution of the shallow water tidal components gradually increases.