Abstract: The Dabie-Sulu Orogen has been recognized as an ultrahigh-pressure metamorphic terrane in central-eastern China that was produced at Triassic by collision between the Yangtze and North China Plates. Stable isotope studies were carried out for ultrahigh-pressure metamorphic rocks from the Dabie-Sulu Orogen in east-central China.The results show not only 1oca1 oxygen isotope anomaly with the extremely low δ18Oof -10‰ in coesite-bearing eclogite but also heterogeneous oxygen isotope ratios with δ18O varying from -10‰ to + 10‰.The former indicates that eclogite protolith underwent meteoric-hydrothermal alteration before UHP metamorphism and the subducted plate has the nature of continental crust,whereas the latter suggests rapid subduction of the Yangtze Plate otherwise oxygen isotope homogenization would be attained.Preservation of the negativeδ18O anomaly in the eclogite indicates very limited crust-mantle interaction during UHP metamorphism at mantle depths.As a result,a short period of 5 t0 10Ma is reckoned when the plate containirig the eclogite precursor was subducted into mantle depths greater than 200km , so that no oxygen isotope reequilibration was achieved between the 18O depleted eclogite and the hot mantle.Oxygen isotope geothermometry yields concordant temperatures of 650 to 750℃ for different mineral pairs that have a large difference in oxygen diffusivity,and the isotope temperatures are in agreement with the petrological temperatures of 600 to 800℃ from cation exchange thermometry. Thus oxygen isotope equilibrium among the minerals has been frozen in at eclogite-facies conditions, and no significant retrograde exchange took place during eclogite exhumation.This points to a process of rapid decompression or cooling subsequent to the UHP metamorphism ,corresponding to rapid ascent of the UHP metamorphosed s1ab.These isotope results provide geochemical constraints on the geodynamics of the Yangtze continenta1 plate,and the bulk period for this cycling is estimated to be about 10 to 20Ma.An ice-frying mode1 is therefore advanced for the rapid subduction,the short UHP metamorphism , and the rapid exhumation of the Yangtze Plate.