Abstract:The late Mesozoic was an important period of subduction of the paleo-Pacific Plate to develop the East Asian continental margin intensively with magmatic activity in the South China block. In this paper, the sandstone samples of Shimentan formation (2031~2097 m) and Mingyuefeng formation (1755~1806 m) that closely adjoin the Mesozoic granite basement were selected from the well FZ211 in Lishui sag, East China sea, for the analysis of detrital zircon U-Pb isotopes and trace elements. We obtained the evidence of two major magmatic events that activated in Jurassic（180~160Ma）and in Cretaceous （140~80Ma）,respectively, in which an age range of 120-80 Ma occurred as a major age component. The dated detrital zircons from two episodes of magmatism are characterized by low temperature (605~792℃), fluid-mobile element U, Th, and LREE enrichment, and high field-strength element Nb, Ta, Ti, and HREE depletion. They were formed in a typical magmatic arc tectonic environment. Compared with the oceanic-type zircon, the U/Yb ratios (0.1~5.1) of dated igneous zircons fall the range of the continental-type zircon, but showing a transitional trend towards the type of oceanic zircon in the Cretaceous. The Yushan uplift from the East China Sea, as a sediment provenance for the dated samples, should be an important part of the late Mesozoic magmatic arc, with a period of 120-80Ma strongly for subduction and magmatic activity. The Yushan magmatic arc, if connected with units of the Fuzhou forearc basin and SW Japan-Taiwan accretionary complexes, constitutes an architecture of late Mesozoic continental margin of East China Sea, controlled by the subduction of Paleo-Pacific slab rollback.