Based on the analysis of the unconformity internal Jurassic to Lower Cretaceous， the characteristics of sedimentary，deformation metamorphism and magmatic activity at that time in the North—Central Gangdese and its adjacent area，the paper first proposes that the North— Central Gangdese was being arc basin system in Early—Middle Jurassic，Southern Qiangtang block collided with the Gangdese terrane from Middle Jurassic to the early stage of Early Cretaceous， thrust activities took place strongly and produced foreland basins in Bangong—Nujiang zone and Shiquanhe—Jiali zone at the same time. The North—Central Gangdese and its adjacent area was being postorogenic environment in Middle—Late Cretaceous，meanwhile，mantle material upwelling and convection，producd extensional volcano—sedimentary basins which superimposed on the North—Central Gangdise—southern Qiangtang collisional orogenic belt，magma intrusion activities was strongest than before. The superimposed basin recorded the two evolution stages of early volcano rift and late depression，they resulted respectively form mantle material upwelling and its cooling depression. The conclusion has important significance for the Mesozoic tectonic evolution of Southern Xizang(Tibetan) plateau.