Abstract: Discovery and reestablishment of the ocean plate stratigraphy unit (OPS) and rock assemblage sequence in the complex collisional orogenic belt during the large scale ocean-continent conversion are important geodynamical and geological frontier issues. This paper reported new discoveries of the ocean plate stratigraphy including the ocean island, seamount, intra-oceanic arc, wedge-top basin, and oceanic basin, which are exposed at the eastern part of the Gangdese metallogenic belt and the Indus-Tsangpo Suture Zone in the Southern Tibet Plateau. Through detailed research on their rock assemblage sequence, occurrence, deforming, metamorphism, formation age and tectonic setting, we recognized that (1) the ocean plate stratigraphy unit is an important part of the accretionary complex, which is the result of the continental accretion in the southern Tibet Plateau during the Tethys evolution; (2) It is a continuous evolution from the paleo-Tethys ocean to neo-Tethys ocean in the Southern Tibet Plateau; and (3) The Mesozoic southern Gangdese belt is characterized by its geological setting of the neo-Tethys accretionary wedge, accretionary arc and the accretionary wedge. It is an important part of the thickening new lower crust at the southern margin of Gangdese, facilitating the formation of porphyry copper deposits in the areas.