Abstract: Beidacheng gold deposit occurs in the metamorphic rocks of the Archean Xiaotazi formation of Liaohe group and was controlled by NE ductile-brittle shear belt. The ore body presents as vein structure. Two mineralized types are pyrite-quartz vein and altered rocks. The mineralization has positive relations with alteration. Ore sources are provided by the Archean amphibolitic formation, and have genetic relationship with Yanshan supergene-ultra-supergene quartz-orthophyre and rhyolite porphyry. Sulphur isotopic compositions correspond to meteoritic sulfur. The mineralization temperatures are mainly between 120℃ to 270℃. It belongs to magmatic metamorphic hydrothermal reconstruction Au deposit of medium-lower temperature.