The Yinshan polymetallic deposit, a superlarge, volcanic-subvolcanic hydrothermal deposit in Jiangxi Province, China, is characterized by complex multi-phase, multi-stage ore-forming processes and well-developed ore zoning. The main metallization is volcano-subvolcanic hydrothermal metallization, which was preceded by dynamohydrothermal metamorphism resulting from ductile-brittle shearing. On the basis of the tempo-space relations of the orebodies with sub-volcanic rocks of three cycles, the volcano-subvolcanic hydrothermal metallization may involve two metallization phases and five stages. A geochemical study on the deposit suggests that the metallization be characterized by southward migration in space. Numerical modeling of fluid dynamics suggests that tectono-magmatic pulsation and the occurrence of the concealed igneous body be the cause for the directional migration of metallization. The writer holds that there is a concealed igneous body at depths in the ore district but that the discovery of a concealed porphyry copper deposit is not very promising.