Abstract: The present authors rose the idea of Meso-Neoproterozoic Jiangnan island arc caused by a northwestward subduction of the paleo-South-China oceanic plate in 1970s. Since that the studies on the Jiangnan island arc has become a hot point of tectonic research oil east Asia in 1980s and early 1990s. Represented by the dismembered ophiolite suite having Sm-Nd ages of 1295Ma and 1734Ma and the uppermost sedimentary age of 988Ma of ‘‘Chencai Group” to the south of Jiangshan Shaoxing fault zone, the oceanic crust of paleo-South-China plate suhducted northwestward under the southeast margin of the Yangtze plate, resulting in the formation of the Anhui-Zhejiang-Jiangxi Meso-Neoproterozoic island arc (Huiyu island arc), northeastern segment of the Jiangnan island arc. The island arc mobilized in the age range of 980-1200Ma, which implied that the oceanic crust suhduction had lasted until 980Ma. The Fuchuan ophiohte to the north of the island arc represented the oceanic crust of a marginal sea, which ranged from 935Ma to 1024Ma roughly coincided with island arc in time. In fact, the northeast Jiangxi ophiolite belt (930～1150Ma) rending in northeast is nor located on the Jiangshan-Shaoxing fault zone but tends to be extended to the Fuchuan ophiolite, southern Anhui. Not only the northeast Jiangxi ophiolite is identified as the marginal sea type by petrochemistry and REE analysis, hut also the matrix graywacke of ophiolite blocks is proved as the back arc basin sediment. Therefore, taking the Jiangshan-Shaoxing fault zone as the subducdon zone, Anhui-Zhejiang Jiangxi volcanic island arc located to the north, and the Zhangshudun-Fuchuan as the back arc basin to the north of the arc in turn, a trench arc back arc basin system with the northward/northwestward polarity of plate subduction is reasonably disposed in spatial relationship. This is the typical model of the Jiangnan Meso-Neoproterozoic trench-arc-back arc basin system. An ape are collision event between the Chencai arc and Anhui-Zhejiang Jiangxi arc occurred during 980～770 Ma, which resulted in the intensive deformation of island arc rocks, the formation of collision type granites in the Anhui-Zhejiang-Jiangxi arc-and the deposits of late Mesoproterozoic, Stenian-Early Neoproterozoic, Tonian flysch and molasse which over laid the arc rock assemblage unconformably (Shengong movement)and of the S／man which overlaid the Tonian strata unconformably (Xuefeng movement). The collision also resulted in the collapse of the Zhangshudun-Fuchuan back arc basin, proved by the blueschists with the K Ar age of 866 14Ma. The oceanic crust subducted northward and that finally led to the processes of orogeny of back are continent-arc collision with a series of thrusts in the southeastward tectonic transportation direction. On the southern flank of the back arc basin, there possibly existed the southward subduction which related with the formation of a short life local volcanic rock assemblage (Shangshu formation of Tonian). The Late Neoproterozoic early Paleozoic sinistral strike slip faulting and the Late Paleozoic—early Mesezoic southward thrusting and gravitational nappe occurred in the southern flank of the Anhui-Zhejiang-Jiangxi paleo-island arc. The later deformation processes involve Carboniferous Permian radiolaria siliceous shales into the melange along northeast Jiangxi fault zone, the remains of Zhangshudun-Fuchuan marginal sea. The komatiite in the Jiangnan Meso-Neoproterozoic trench-arc back arc system implies that the processes of Isu collision model displayed there, which occurred in the situation of high heat flow. The Shengong movement in eastern Zhejiang occurred around 980Ma implied the collision between the Chencai arc and Anhui-Zhejiang-Jiangxi arc. This a arc collision event lasted until 770Ma, which is the early stage of Sinian. The Xuefeng movement recorded the late effect of the collision event. The time of unconformity surfaces vary from place to place, because the spatial and temporal variation of the collision events. That implies that the crust movement represented by the unconformities would exhibit diachronism and the correlation of unconformities is qualitative only. The northeast segment of Jiangnan Meso-Neoprorerozoic island arc collision orogenic belt is divided into following tectonic facies: Jiangsban-Sbaoxing fore-arc suture zone, Chencai mobilized basement, Anhui-Zhejiang-Jiangxi volcanic arc as part of overriding plate, Zhangshudun-Fuchuan back are suture zone.