Abstract: Amdo gneiss which exposed in south of Amdo County about 30km, in the northern Tibet constitutes the major lithologic of Nierong Group on Nierong microcontinent. Nierong was a large micro-lens gripping Gangdise-Nyainqentanglha plate of northern Tibet and Qiangtang-Sanjiang composite plate in the Bangong Co-Nujiang River suture zone. The CL images of biotite-monzonite-gneiss zircons show distinct oscillatory zoning. Th/U ratios range from 0.63 to 1.04 with an average of 0.85. Gneiss zircons LA-ICP-MS U-Pb in situ isotopic age is 488.0±4.2 Ma. Dating results show that the Amdo gneiss protolith was emplaced in the Pan-African period, and verifies that Nierong microcontinent was effected by the late Pan-African thermal motion. This study provides an important chronological evidence for basement properties and tectonic evolution of the Nierong microcontinent.