Carboniferous volcanic rocks in Altay, Xinjiang, mainly exist in its northeastern part.They consist of rhyolite,dacite and cataclastlava.These continental volcanic rocks can be divided into four lithofacies,i.e.effusive facies,airfal l facies,extrusive facies and eruptivesedimentary facies.The volcani c activities occurred from explosion,through eruption to extrusion at last.T hey are rich in K,Rb,Ba and Th and poor in Ti and Yb.The y have high ΣREE contents and show obvious negative Eu and Ce anomalies.Initial Sr isotopic ratios for Carboniferous volcanic rocks are higher than the average value of continental volcanic rocks.Their tectonic setting is the orogenic compr ession belt, and the material components are derived largely from the crust, whi ch are d ifferent from the case of Devonian volcanic rocks in the same area. The related ore dep osit s are volcanichydrothermal ones.