The measuring accuracy of the ZYZY-type Sea Gravity Meter,developed by Seis-mological Institute of State Seismological Bureau,was re-determined by sea gravity data that had been obtained during 1977-1979 in the study regions.The basic contours of free-air gravity anomalies,Bouguer anomalies and crustal thickness etc.were compiled.The characteristics of the crustal structures for the region in question were investigated with reference to geological and geophysical data.