Objectives：The Ailaoshan tectonic belt is situated at the contact site of Tethys—Himalaya tectonic region and coastal Pacific tectonic region. At present, it is still controversial that whether Jinshajiang—Ailaoshan tectonic belt exists paleotethys ramose ocean basin or not in late Paleozoic era. In regard to this dispute, we focus on the study of petrogeochemistry and zircon UPb chronology of the Fengbieshan felsophyre in Yunnan to evaluate geological evolution in late Paleozoic era in southern section of Ailaoshan tectonic belt.Methods：Factitious heavy fraction was conducted to select zircons from the fresh sample of PM3005Z and wellcrystallized, crackless, and transparent zircons were selected under the microscope，then photos of zircons were taken under reflected light and transmission light and CL image. The U-Pb isotope analysis was carried out at the laser probe of LA-ICP-MS Elan6100DRC in isotope geochemistry national key laboratory of Guangzhou Geochemical Institute. The analysis of major element compositions was completed with fluorescent spectrometer (XRE) of Rigaku RIX 2000. The analysis of trace element compositions was performed with inductively coupled plasma source mass spectrometer (LA-ICP-MS) of PerkinElmer Sciex ELAN 6000.Results：LA-ICP-MS zircon UPb dating results show that the Fengbieshan granodiorite formed in the Late Permian (263.6 ±2.4Ma). The Fengbieshan granodiorite is characterized by SiO2 62.10%~63.09%, alkali (Na2O+K2O) 6.28%~7.21%, and Na2O＞K2O. Moreover, it is enriched in LREE and Sc, Hf, and depleted in Sr, Zr, Th, U , with negative Eu anomalies ( δEu：0.84~1.32 ).Conclusions：According to the analysis data, we consider that the Fengbieshan granodiorite formed in the tectonic environment of island arc—continent or continental—arc collision, indicating that the branch of PaleoTethys Ocean or arc basin in Ailaoshan tectonic belt may have been closed in the Late Permian ( 263.6 ± 2.4Ma ).