Abstract: Geophysical technology is the main and primary mean in marine geological survey for revealing shallow geological structures under water. In deep water, however, the seismic data are often interfered by outside factors as the energy of effective seismic waves is weakened with water depth. For instance, the identification of igneous rocks is always difficult using only seismic data. On the other hand, gravity and magnetic anomalies are those which respond effectively to some geological bodies with high density and/or magnetism, such as faults and igneous rocks, and often used as a guide to tectonic division. However, multiple solutions always occur in the interpretation of gravity and magnetic data due to various variables. In view of this, integrated interpretation of gravity-magnetic-seismic data is the only choice to fully use the advantages of the three methods to improve the reliability of interpretation. The paper takes the northeastern sea area of China as a case to make an integrated interpretation of gravity, magnetic and seismic data for the distribution pattern of faults and igneous rocks. Upon the basis, a new tectonic division of the area is presented.