Abstract: Sm—Nd isochron dating and O isotope an alysis were carried out for minerals from eclogite at Jinheqiao in Dabieshan．Garnet+omphacite Sm-Nd line gives an age of 210±3 Ma．and garnet+ rutile， 237 ± 4 Ma． Amphibole occurs as corona around omphacite， indicating significant retrograde reaction during exhumation． Correspondingly， O and Sm-Nd isotopic disequilibria were observed between omphacite and garnet，resulting in an unreasonably low Sm-Nd isochorn age of 210±3 M a．Mineral-pair O isotope thermometers yielded a temperature of 695±35℃ for a quartz-garnet pair and 460±15℃ for a quartz-rutile pair．Sm-Nd isochron defined by garnet + futile with an age of 237±4 M a records the eclogite-facies prograde metamorphic time，which is considerably higher than rutile U—Pb age of 218.2 ± 1.2 Ma from the same sample．A1l these data suggest that the rate of 0 diffusion in garnet is slower than，or close to that of Nd diffusion in garnet，wheress the rates of 0 and Pb diffusion in rutile are faster than those of Nd diffusion in rutile．0 isotope an alysis on different grains of rutile gave consistent results within an alytical uncertainty；the O isotope temperature defined by the quartz-rutile pair is in agrement with a closure temperature of 470±50℃ for Pb diffusion in futile as estimated from the futile U—Pb isochron dating ． These indicate that O an d Pb isotopic homogenization was achieved among different grains of rutile in the scale of han d specimen during the eclogite-facies metamorphism ，and that the rates of 0 an d Pb diffusion in rutile are similar to each other during eclogite cooling ．