Abstract: This paper focuses on the study of the height transference within long distance across sea,by combining ellipsoidal height of GPS with gravimetric geoidal height.Using this method,the Yellow Sea Height Datum is transferred to Yangshan Island which is 30 km faraway from Shanghai. As an external check,the transferred heights of stations by the method are compared with those determined from two independent sets of gauge records,and the differences are 1.0 cm and 6.0 cm respectively.Moreover,the transferred height difference of two sections between the stations on the island are also compared with the measured ones precise leveling,which shows that the differences are 0.2 cm and 0.7 cm respectively.