Abstract: The sea surface topography along China's coast and the differences of the MSL between several tidal gauges and Qingdao datum level surface have been estimated using SST models proposed by Engelis using SEASAT altimater data and by Levitus using ocean levelling.The computation of the models with geodetic levelling connecting some tidal gauges shows that general trend of the sea surface slope is basically agreement with each other, i.e. going upwards in the direction from north to south along the coast of Huanghai sea (Yellow Sea) and Donghai Sea (East China Sea), and downwards along the coast of Nanhai Sea (South China Sea).Due to the existing effects of the SST and the zero degree term no for geoidal unduletion, if the separation are computed using China's local gravity anomalies near the computation point (Ψ₀=10°, for example), then the errors for geoid could reach 0.4m. Thus, the errors, for a determination of geoidal undulation with an accuracy of one meter, should be considered.