Abstract: Granites are important components in the continents, and also closely related to mineral resources. Granites take c. 12% of the total area of Tibetan territory and about 80% （in area） of them are distributed in the Gangdese magmatic belt. Spatially, the Gangdese granitoid belt consists of three zones, i. e. , north, middle and south zones, as a result of the evolution of Neo-Tethyan Bangong Co-Nujiang ocean and Yarlung Zangbo Ocean. Temporally, the tectono-magmatie events in the Tibetan Plateau and the Gangdese can be divided into three stages： Pre-collisional （ 〉65 Ma）, syn-collisional （65 -45 Ma） and post-collisional （ 〈 45Ma）. Nd and Sr isotopes of granitoids in the Gangdese provide a hint for understanding the crust growth and evolution. Most of granites in southern Gangdese have positive values of εNd （t） （ ＋ 1. 64 - ＋ 5.21 ） and young Nd model ages tDM （ 〈500 Ma）, showing characteristics of the juvenile crust. It implies that the mantle material played a significant role in granite petrogenesis. Granites in middle and northern Gangdese, however, are characterized by negative εNd（t） （ -5.3 - - 17.3） and relatively older tDM, 1. 2 Ga and 2.0 - 2.5 Ga, implying a Neo- and Paleo-Proterozoic basement. Crustal material played a major role in granite petrogenesis for the latter case.