Abstract: A 3-D hydrodynamic model is established used an unstructured triangular grid known as the finite-volume coastal ocean model （FVCOM） to resolve the irregular coastline and bathymetry in the coastal regions. The simulated results are in good agreement with the long-term observed data and reproduce the distribution features of the tide and tidal currents in Taiwan Strait. The distributions of co-tidal charts and tidal ellipse on the surface layer for 4 major constituents （M₂、S₂、K₁、O₁） are obtained by T_tide toolkit. The results show that the southward and northward tidal waves of M2 tide from the Pacific into Taiwan Strait converge between Penghu Islands and south of Taiwan Shoal in the direction of NE—SW and the maximum amplitude is 2.45m and it appeared in the areas of Xinghua bay and Meizhou Bay. K₁ constituent incoming wave propagates from northeast to southwest toward the South China Sea， the amplitude of which in the right side of forward direction is 0.05m higher than the left's. There exists a dividing line on which the ellipticity of constituent tidal is zero in Taiwan Strait. The line direction is NE—SW， at the upper part of which the direction of rotation is counterclockwise， the lower is clockwise. Four major tidal currents to the major axis of the ellipse are in NE—SW direction and in the nearshore region and the discontinuous terrain such as Taiwan Shoal are in NW—SE direction，while in Penghu Channel they are in N—S direction. The major axes of 4 tidal currents in the Taiwan Shoal are large and the corresponding trend is also large due to the influences of local shallow depth．