It is hoped that this paper will be of some help to the discussion on geo--physical field, infrastructure and metallogenic specialization of granitoids in southeastern China and their connection with endogenic mineralizations.The crust and upper mantle model established by means of deep seismc sounding and gravity anomalies serves as the basis for division of crustal types and metallogenic prognosis, and the Moho depth and the crustal nonniformityseem to be the major criteria for division of regional metallogenic belts. The simulation and interpretation of regional gravity anomalies confirm the existen ce of relationship between W-Sn metallizations and Moho depression and low density zone in lithosphere as well as the relationship between Cu-Fe, Pb-Zn metallogenic belt and Moho uplift and steep slope zone.Due attention is also paid to the relationship of metallogenic provinces to local gravity and magnetic anomalies, chemical composition of intrusive bodies and deep faults in various directions. The metallogenic specialization of the gra nitoids is determined according to magnetism of rocks and petrochemical para meters.With the help of gravity simulation, the three dimensional shape and in terior structure of the granitoids at depth are determined, and this contributes to ore prospecting at depth and the research on ore potentiality of intrusives.The data obtained in southeastern China demonstrate the effectiveness and prospects of applying the gravity and magnetic field to the study of crustal structure, magmatic rocks and ore prognosis.