Abstract:The Lancang group, an important part of the Tethys orogenic belt, is located in the Changning?Menglian combined belts in the Sanjiang area of western Yunnan, China. In this paper, we conducted zircon U?Pb dating, Hf isotope and petrogeochemistry of albite-granulite, whose discussed the genesis, forming Age and geotectonic evolution of the rocks in the Shuangjiang area. The detrital zircons with strongly oscillatory zoning is typically magmatic origin from albite-granulite, which were employed for dating. U?Pb dating is 476.5±1.6Ma about weighted average of 206Pb/238U, which is Early Ordovician (O1).In situ analysis of Hf isotopes, the εHf(t) is ?5.6～?2.2 and the TDMc Age is (1591～1802) Ma, indicating that the materials in the source area were formed by partial melting of ancient crustal materials during from the terminal of Early-Proterozoic to the early of Middle-Proterozoic . According to petrogeochemical analysis, the original rock of albite-granulite is granitic diorite which are peraluminous S-type granite with High SiO2= (67.89～68.91) %, Aluminum-rich Al2O3= (14.48～15.14) % and High potassium calc-alkaline. The characteristics, enrichment in LREE, tilted the overall "right", δEu(0.60～0.64)and strong negative Eu, indicated that plagioclase crystallization have separated from magma.The analysis shows that the original rock of albite-granulite is island-arc granite, which formed in the continent-arc collision stage about Changning?Menglian Tethys, has the same tectonic background as the volcanic rocks of the Huimin formation in the Ordovician. As Tethys entered intracontinental subduction?grinding stage, the island-arc granite is a subduction accretionary complex, between the Changning?Menglian combined belts and the Lincang Batholith, forming tectonic sheet of the Lancang group.