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A big mantle wedge (BMW) is an important deep Earth structure that has implications for our understanding of geodynamic processes. The eastern and northeastern Asian BMWs have been extensively studied in the past two decades. This paper reviews evidence for the age, formation, spatial extent, and geodynamic effects of BMWs, with the aim of distinguishing between two BMWs. The eastern Asian BMW initially formed in the late Early Cretaceous and was active from 110 to 55 Ma due to rollback of the subducted Paleo-Pacific Plate and eastward-directed deep mantle flow. This BMW affected the entire eastern Asian continental margin and controlled the late Mesozoic–early Paleogene tectonic evolution of the margin, including destruction of the North China Craton and reworking of continental crust in South China. The northeastern Asian BMW has been active from 20 Ma to the present-day due to rollback of the subducted Pacific Plate and eastward mantle flow. It has mainly affected northeast Asia and resulted in different types of Cenozoic intraplate volcanism and occurrence of earthquakes with deep epicenters. • Eastern (E) and northeastern (NE) Asian big mantle wedges (BMW) are identified. • E Asian BMW formed in late K1 and controlled late Mesozoic-early Cenozoic evolution. • NE Asian BMW formed at ca.20 Ma and controlled intraplate volcanism and earthquakes. [ABSTRACT FROM AUTHOR]