Here, we examine spatiotemporal variations of Jurassic–Cretaceous magmatism along a c. 1000-km transect across eastern Asia, including SW Japan, the Korean, Jiaodong and Liaodong peninsulas, and eastern Jilin Province. Integration of tectonic regime data with age data from igneous rocks in eastern Asia (from the Tan-Lu Fault to SW Japan) suggests a shallowing of the subduction angle and subsequent flat-slab subduction during the Jurassic, and slab rollback during the Early Cretaceous. The combination of a subducting plateau and root-enhanced suction provides the best explanation for the flat-slab subduction. In the final stage (Albian) of slab rollback, the geotectonic setting changed from subduction–accretion to a continental arc in the area close to the ancient trench (i.e. the Inner Zone of SW Japan).