in situ analyses of oxygen isotopes were carried out by ion micro-probe for zircons from 8 localities of HP-UHP metamorphic rocks including eclogites in the Dabie-Sulu terrane. The results show significant heterogene-ity in d 18O values, with variation in different rocks from 8.5 to +9.7 and within one sample from 2 to 12. No measurable difference in d 18O was observed between proto-lith magmatic (detrital) zircons and metamorphic recrystal-lized zircons within analytical uncertainties from the ion micro-probe measurements. This indicates that the meta-morphic zircons have inherited the oxygen isotopic composi-tions of protolith zircons despite the HP to UHP metamor-phism. According to their protolith ages from zircon U-Pb in situ dating by the same ion micro-probe, two groups of oxy-gen isotope composition are recognized, with one having d 18O values of 6—7 for old protolith of 1.9—2.5 Ga ages and the other 0—2 for young protolith of 0.7—0.8 Ga ages. The latter anomalously low d 18O values of zircons in-dicate that the magma has had the obvious involvement of meteoric water when forming the young protolith of high-grade metamorphic rocks. This may be correlated with the snowball Earth event occurring in South China and the world elsewhere during the Neoproterozoic. in situ analyzes of oxygen isotopes were carried out by ion micro-probe for zircons from 8 localities of HP-UHP metamorphic rocks including eclogites in the Dabie-Sulu terrane. The results show significant heterogene-ity in d 18O values, with variation in different rocks from 8.5 to +9.7 and within one sample from 2 to 12. No measurable difference in d 18O was observed between proto-lith magmatic (detrital) zircons and metamorphic recrystal-lized zircons within analytical uncertainties from the ion micro-probe measurements. indicates that the meta-morphic zircons have inherited the oxygen isotopic composi-tions of protolith zircons despite the HP to UHP metamor-phism. According to their protolith ages from zircon U-Pb in situ dating by the same ion micro-probe, two groups of oxy-gen isotope composition are recognized, with one having d 18O values ​​of 6-7 for old protolith of 1.9-2.5 Ga ages and the other 0-2 for young protolith of 0.7-0.8 Ga ages. The latter anomalously low d 18O values ​​of zircons in-dicate that the magma has had the obvious involvement of meteoric water when forming the young protolith of high-grade metamorphic rocks. This may be correlated with the snowball Earth event occurring in South China and the world elsewhere during the Neoproterozoic.