The Dahegou Antimony ore deposit occurs mainly in the metamorphic rocks of Mesoproterozoic Qinling Group, with orebodies controlled by the Shuangkuishu deep fault and its nearby fractures. The deposit should belong to a structurallycontrolled lowtemperature hydrothermal deposit. In order to understand the relationship between mineralization structures and metallgenic element enrichment, and mineralization mechanism, we carried out a detailed study of tectonite using mineralogy, isotopic geochemical analysis and fluid inclusion testing. The results show that the distribution of the deposit is controlled by regional ductile shear zones. The mylonitizatioin occurred at 1986±474 Ma and mineralization elements sourced from deep earth. The stibnites were possibly formed under a single, closed environment, and are of typical peak features, and contain high concentrations of Au, Ag, Mo, Hg, Pb and Zn. Carbon and oxygen isotopes of calcite suggest a magmamantle source. The δ 34S values of stibnite range from 371‰ to 385‰, while lead isotopes of stratum lead show similar composition of that of stibnites. Composition analyses of fluid inclusions suggest that the fluids were mainly hydrothermally modified sedimentary brines consisting sulfate and locally bicarbonate type aqueous solutions. The mineralization occurred under reducing conditions. The mineralization occurred in the reducing condition. The high content of H2 in fluid inclusions of quartz indicates that the oreforming fluids are characteristic of deep source. Integrated study indicates that the ore deposit formed from precipitation of metallic elements in the reducing and lowtemperature condition, which were extracted from ductile shear zones when migrating along deep faulting. Therefore, the Dahegou antimony deposit can be determined a structurefluidcontrolled metamorphic deposit.