Abstract: Nd-Sr isotopic compositions of 58 granitoid bodies in SE China are reported in this paper. Based on these data and previously published isotopic compositions of other 127 granitoid bodies and comparison with Nd isotopic compositions of basement metamorphic rocks, we studied the Nd-Sr characteristics of granitoids of various ages in SE China and their sources. The Palaeoproterozoic grantoids are only distributed in southeastern Zhejiang province within the Cathaysia Block. These granitoids have εNd: -6.2 to-3.0 and initial 87Sr/86Sr ratio (Isr) of 0.7083 to 0.7l17. On the εNd-t diagram they are plotted within the evolution zone for the Palaeoproterozoic metamorphic rocks in the same region. This suggests that these Palaeoproterozoic granitoids be formed by partial melting of rocks similar to the Palaeopmterozoic metamorphic rocks. The Neoproterozoic granitoids in SE China are distributed in the southeast margin of the Yangtze Block. The Neoproterozoic granitoids distributed along the Jiang-Shao Fau1t Zone have high εNd value (2.0 to 4.2), low Isr value(0.7011 to 0.7032) and low δ18O value(6.3 to 6.7‰) which are similar to those of middle Proterozoic spilite-keratophyre of Shuangxiwu Group. Therefore, these granitoids may have been derived from a mantle source similar to the source for the spilite-keratophyre, or from partial melting of juvenile crust consisting mainly of spillte-keratophyre. The Neoproterozoic granitoids in western Zhejiang, southern Anhui and northern Jiangxi provinces have εNd: -0.4 to -2.2, Isr=0.7040 to 0.7064 and δ18O=10.5 to 11.7‰. On εNd-t diagram, they are plotted in upper part of the evolution zone for the middle Proterzozic metasediments of the Shangxi Group and Shuangqiaoshan Group. This suggests that they be derived from the low maturity components of basement metamorphic rocks in this region. Almost all Paleozoic granitoids are distributed in the Cathaysia Block. They have variable isotopic compositions (εNd= -18.1 to -2.1, Isr=0.7071 to 0.7287). On εNd-t diagram, most granitoids are plotted within the evolution zone for the middle Proterozoic basement metasediments, suggesting they be derived mainly from crustal materials. Mantle component was involved in formation of sonic Paleozoic granitoids. Mesozoic granitoids are distributed all over SE China. Their isotopic compositions are evidently variable(εNd=-16.4 to 1.9, Isr=0.7043 to 0.7404). On εNd-t diagram, more than half of the granitoids are plotted above the evolution zone for the middle Proterozoic crust in the region, indicating their crustal derivation. However, many granitoids mainly distributed at the coast of Zhejiang and Fujian provinces are plotted above the evolution zone for the middle Proterozoic Crust in the region, suggesting more mantle-derived materials in their sources. These granitoids may have been formed by mixing of the basaltic magma induced by subduction of the Pacific Plate in the late Mesozoic era with the felsic magma formed during partial melting of crustal rocks caused by underplating of basaltic magma.