Abstract: The metamorphic basement in the Hainan Island is mainly composed of Baoban and Shilu Groups. The Baoban Group is dominated by am phibolite-facies gneisses，metasedimentary rocks(quartz muscovie biotite schists)，whereas the Shilu Group consists mainly of metamorphic volcano-sedimentary associations. There also occur voluminous granitic plutons of different ages from the Mid-Proterozoic to the Late Mesozoic indicating multi-stage modification and complicated accretion history of the crust Nd and Pb isotope data of 63 samples in different lithological associations in Hainan Island demonstrate that the major crustal accretion age ranged from the Early Proterozoic to the Late Proterozoic, with three peak stages of 2.0 Ga,1.7 Ga and 1 2Ga. The regional crust is characterized by low degree of maturation, and the mafic metamorphic basement was mainly derived from a chronically depleted mantle source The εNd(t) values for the Baoban Group vary from 2.2 to 2.8，with the TDM mainly about 2 00Ga and εNd(t) values for Proterozoie metabasic rocks vary from 4.7 to 8.1 The granitic plutons of different ages generally show higherεNd(t)values( -19.1～-35 for the Proterozoic granitic plutons and -6.3～ -O.1 for the Phanerozoic granitic plutons)and lower TDM values(1.68～2.02Ga for the Proterozoic granitic plutons and 0.99～ 2.34Ga for the Phaneromic granitic plutons)than those in southeast China， suggesting their origin from a younger lower/middle crust with involvement of depleted mantle-derived materials The Pb and Nd isotope data of the metamorphic basement in Hainan Island are~mewhat different from those in the Cathaysia Block and Yangtz Block， indicating that the metamorphic basement of these three blocks might be different in formation ages and evolution histories The metamorphic basement beneath the Hainan Island should not be regarded as the southern extended segment of the Cathaysia Block.