Abstract: The extensional tectonic events during the Late Mesozoic were widely distinguished in the east central part of the South China Plate.These events are characterized by red sedimentary basins, dome extensional structure, metamorphic core complex, ductile detachment fault zone, and simultaneous large-scale of syntectonic magma and metallogenic processes.But the late Mesozoic extensional deformation sequence of the region is still controversial, especially the formation ages of rapid extension.In this paper, the authors focus on the time of intensive extension of the Lushan magmatic core complex(LMCC)in middle-east part of the South China Plate.Field investigation was carried out to analyze the syntectonic deformation of the ductile shear zone on both sides of the LMCC and its periphery.The new results show that the detachment normal fault of shear zone has NW-SE extensional direction, and ⁴⁰Ar-³⁹Ar dated the apparent main plateau ages of muscovite and biotite at 105.20±0.23 Ma and 95.84±0.09 Ma, respectively.The uplift-rapid extension formation age of LMCC is thus concentrated at 95~105 Ma.It is noticeable that the extensional deformation of the characteristics and formation age of the LMCC is consistent with the regional extensional deformation of the Southern China Plate.The uplift-rapid extension formation of LMCC represents a rapid extensional tectonic deformation event in the South China Plate since the Late Mesozoic.The formation mechanism of the uplift-rapid extension formation of LMCC may be associated with rollback after the Paleo-Pacific Plate had subducted into the Southern China Plate.