By use of the hydrodynamic model, the harmonic constants of 8 principal tid
al constituents (Q(1), O-1, P-1, K-1, N-2, M-2, S-2 and K-2) are obtained f
or the East China Sea, and the harmonic constant of S-a is calculated by tw
o-dimensional interpolation. The calculated results agree well with the obs
erved data around the sea. The harmonic constants can be used to predict th
e tide in the East China Sea. The cotidal charts of the 9 tidal constituent
s reveal their distribution.