—In this paper,integrating the Yangtze Estuary with the Hangzhou Bay,a 2-D velocity fieldmodel is established.In the model,fine self-adaptive grids are employed to adapt to the complicated coast-al shape.The hydrodynamic equations satisfied by two contravariant components of velocity vector andsurface elevation in non-orthogonal curvilinear coordinates are used.In each momentum equation thecoefficients before the two partial derivatives of surface elevation with respect to variables of alternative di-rection coordinates have different orders of magnitude,i.e.,the derivative with the larger coefficient mayplay a more important role than that with the smaller one.With this advantage,the ADI scheme can beeasily employed.The hydrodynamic factors include tidal current,river runoff and wind-induced current.In terms of tidal current,seven main constituents in the area are considered in the open boundaries.Theverifications of surface elevation process and current velocity process in the spring tide and in the n -In this paper, integrating the Yangtze Estuary with the Hangzhou Bay, a 2-D velocity fieldmodel is established. The model, fine self-adaptive grids are employed to adapt to the complicated coast-al shape. The hydrodynamic equations satisfied by two contravariant components of velocity vector and surface elevation in non-orthogonal curvilinear coordinates are used. each momentum equation thecoefficients before the two partial derivatives of surface elevation with respect to variables to alternative di-referencing coordinates have different orders of magnitude, ie, the derivative with the larger coefficient mayplay a more important role than that with the smaller one. This advantage, the ADI scheme can beeilyily employed. hydrodynamic factors include tidal current, river runoff and wind-induced current. In terms of tidal current, seven main constituents in the area are considered in the open boundary. the verification of surface elevation process and current velocity process in the spri ng tide and in the n