Copper-polymetal minerals occur in the cracks of the Erhuling Formation rhyolitic ignimbrite in Xujiadun, Jiangshan District, Zhejiang Province, but the origin and age of rhyolitic ignimbrite are still unclear. Based on the field observation, it is pink in color and of rhyotaxitic and porphyritic structures. REE geochemical analysis shows high negative Eu abnormalities (δEu=0. 028~0. 038)with a “seagull-shaped” distribution in REE patterns. Petrography and geochemical characteristics indicate that the rhyolitic ignimbrite is of A-type granite, suggesting it formed in an intraplate structural environment. SHRIMP zircon U-Pb dating yields an erupting age of (138.0±2.4) Ma, indicating that the volcanic rocks likely emplaced at the middle-late stage of Yanshanian movement during the Mesozoic Era.