Abstract: The Honggou copper polymetallic deposit is located in the southwest of Menyuan County, Qinghai Province. The authors conducted the chronological study of zircons from the basic volcanic rocks by means of LA-ICP-MS U-Pb. The weighted mean age of the zircons is 443.2±1.2 Ma, suggesting Late Ordovician. It is considered that the age represents the metallogenic epoch of the Honggou copper polymetallic deposit which was formed in a continental margin rift environment. The high-precision age obtained by the authors is of great significance in the study of ore-forming epoch and genesis of copper-polymetallic ore deposits produced in the epicontinental rift environment of the whole Qilian Mountain region.