Abstract: The tidal current and tide-induced residual circulation of the Bohai Sea are calculated by a numerical model braced on the two-dimensional nonlinear long wave equations with the semi-implicit alternating direction method.As a result, the spafial distributions of amplitudes,phases, tidal ellipses in tide-M₂ and residual current are obtained.The tidal wave systems of M₂ and K₁ of the Bohai Sea are reproduced by the model.The computed co-tidal and corange lines of M₂ and K₁ are well in agreewent with harmonic constants obtained by tide gauge stations.The comparision between the computated and observed values exhibits a considerable agreement. The computation of the tide-induced residual circulation produces a flow pattern with three major eddies, and many minor individual eddies,and this flow pattern is strongly supported by the available oil pollution monitoring.