This paper systematically summarizes recent achievements in fossil accretionary complex studies in NE Asia, together with analysis of spatial—temporal variations of the coeval igneous rock association and sedimentary formations in NE Asia,with the aim of understanding the evolutionary history of the western Pacific subduction zones in NE Asia.The results indicate:(1)that the Yuejinshan accretionary complex represents the Permian subduction zone in the eastern Jiamusi Massif,and resulted from the evolution of the Paleo-Asian Oceanic regime;(2)Jurassic accretionary complex represents the Jurassicn subduction zone in NE Asia,and together with the coeval calc—alkaline volcanic rocks,reveals the subduction onset of the Paleo-Pacific plate beneath the Eurasia;(3)provenance variations of terrigenous clastic rocks within the Jurassic complexes,together with paleomagnetic and biological data,indicate that a small angle of slant subduction of the Paleo-Pacific plate and strike-slip tectonics took place in NE Asian continental margin,resulting in northward movement of the Jurassic complexes from low altitude to high-altitude;(4) Cretaceous—Paleogene accretionary complex represents Cretaceous—Paleogene subduction zone in NE Asia.Toward trench contracting of extents of the Cretaceous—Paleogene magmatisms reveals the westward subduction of the Paleo-Pacific plate and rollback of the subducted slab,and marks the formation of the eastern Asian big mantle wedge;and(5)the opening of the Japan Sea at the end of Paleogene and early stage of Neogene marks the formation of the present Pacific subduction zone and the northeastern Asian big mantle wedge.