Abstract: The practial formulae with more perfection for the solution of tidal differential equations are presented in this paper. Then the tidal charts in a 30'×30' grid,with the boundary points as the known condition and the tide gauge in the sea as the control and check,are computed in the Chinese offshore waters. With the comparisons of in-situ data,it is concluded that the accuracy of amplitude (H) of the partial tide is ±15cm and the accuracy of lag angle (g) is ±20º,meeting completely the requirements of tidal corrections for the hydrographic survey in the sea. Finally,tidal charts and non-tidal points location are given,some propagation features of tidal wave in the Chinese offshire waters are also investigated and analysed. Meanwhile,some useful conclusions are obtained.