As a composite erogenic belt of the Himalaya giant orogenic zone, Yidun arc, Sanjiang region (means three rivers region, i.e. : Jinsha River, Nujiang River and Lancang River), experienced an evolution history including Indosinian subduction orogeny of oceanic crust, Yanshanian arc-continental collision orogeny and Himalayan intra-continental strike-sliding shearing. Probably due to different subduction dipping degrees, the Yidun old arc belt of late Triassic (206 ~ 237 Ma) has a different development history in its northern and southern segments. Changtai arc in the northern segment was characterized by intra-arc rift with expanding nature and developed a fluid convergent ore-foming system in an extentional environment, which formed. VMS-type Zn-Pb-Cu deposits and epithermal Ag-Au-Hg deposits. Zhongdian arc of the southern segment lacked back-arc basin, but had extensive calc-alkaline complex distribution of arc volcanics-porphyry-porphyrite, which formed porphyry-skarn-type Cu-polymetalic deposits. During the arc-continental Collisional process of Triassic-Jurassic boundary, early contineutal plate subduction led to formation of syn-collisional granites(200 Ma). Whereas,late post-orogenic extention resulted in intrusion of A-type granites (75~138 Ma), which was accompanied by development of convergent magma-fluid ore-forming system under an extensional regime and formation of skarn-type tin deposits and fault-controlled hydrothermal Ag-polymetallic deposits. Strong lithospherical shearing and thrusting resulted from Yangtz continental plate subduction caused develorment of a convergent fluid system under a compressional-shearing environment and formation shearing-type Au deposit in the Garze-Litang ophiolitic melange zone. The effect of the Indian-Asian continental collision on the Yidun arc zone was mainly manifested in intra-continental strike-sliding process and alkaline grainte and porphyry intrusion (50~30 Ma). The latter brought us porphyry Au deposits.