Abstract: Dongchuan copper orefield in Yunnan Province is located in Sichuan-Yunnan copper polymetallic metallogenic belt at the western margin of the Yangtze plate.The fracture structure superimposition mineralization and metallogenic effects of Mianshan-Sikeshu metallogenic belt in Dongchuan copper orefield in Yunnan Province are obvious，but the study degree is relatively low.In view of the study shortage，based on the comprehensive cataloging of tectono-lithofacies in the tunnel of Mianshan-Sikeshu metallogenic belt，combined with regional geological background，the fracture elements of typical adit copper orebody are measured，and rose maps are made for analysis and lithofacies zoning.The study results show that:①the alkaline ferric basic magma intrudes into the Luoxue Formation along the large angle fault of Mianshan-Sikeshu metallogenic belt，due to the intrusive and compressive action of magma，the contact zone between intrusive rock mass and strata can be divided into schistose facies zone，hydrothermal breccia facies zone and fractured lithofacies zone from the inside to the outside according to the degree of rock deformation，according to the degree of rock fragmentation，the cataclastic lithofacies belt can be divided into strong cataclastic lithofacies belt，cataclastic lithofacies belt and weak cataclastic lithofacies belt from the inside to the outside，and the grade of copper deposit changes from high to low accordingly；②fractured petrography study reveals that there are mainly three groups of ore-bearing fractures near EW direction，near SN direction and NEE direction，among them，the near EW direction fracture （basically consistent with the occurrence of strata） is the main ore-bearing fracture；③the multi-stage tectonic activities have resulted in high degree of fracture development and complicated intersecting relationship，according to the magma intrusion and transformation metallogenic period，the fractures can be divided into pre-metallogenic fracture，metallogenic stage fracture and post-metallogenic fracture.Based on above study of the characteristics of magmatic intrusive structure-fissure structure system and metallogenic-ore-controlling regularity，it is considered that the copper orebody near the intrusive rock mass of Mianshan-Sikeshu metallogenic belt is obviously enriched by the transformation of the magmatic-fissure tectonic system，and the cataclastic lithofacies belt near the basic rock is a favorable target area for the formation of high-grade fractured deposits.

Key words: Dongchuan copper orefield, Fracture deposit, Metallogenic-ore-controlling regularity, Fracture tectonic system, Lithofacies zonation, Ore-bearing fracture