Abstract:The Yangla copper deposit in northwest Yunnan is the most typical copper deposit in Jinshajiang copper polymetallic metallogenic belt. The structure in the mining area is extremely complex, and the ore body output is obviously controlled by the structure. F4 fault is the most representative NE-trending fault in the mining area, which has a control effect on the rock formation and mineralization of the mining area. In this paper, the F4 fault of Yangla copper deposit is taken as the research object, and the structural characteristics and ore-controlling rules are studied in detail by means of structural analysis and elemental geochemistry.The results show that the overall occurrence of F4 fault is NE40-75°∠30-78° NW, and the rock mass and ore body are obviously cut off. The fault zone is fractured sericite sandy slate, metamorphic quartz sandstone and granodiorite. F4 fault has experienced multi-stage activities. The early stage is compressive-torsional reverse fault, and the late stage is right-lateral tensile normal fault. F4 fault is not only ore-breaking structure, but also ore-conducting structure and ore-hosting structure. The F4 fault zone can be divided into five lithologic-alteration zones : gray-white weakly pyritization coarse-grained marble zone, gray-white tectonic granulite zone, gray-white tectonic granulite-granulite zone, gray-white-yellow tectonic granulite and fault mud zone, and strong limonite mineralization coarse-grained marble zone. The content of ore-forming elements in the fault zone is obviously high, and the upper and lower fractures of F4 fault and NE-trending interlayer faults are enriched in ore-forming elements.