Located in the eastern Awulale metallogenic belt of Western Tianshan Mountains, the large-size Chagangnuoer iron deposit is hosted in andesitic volcaniclastic rocks or andesitic tuff of the Lower Carboniferous Dahalajunshan Formation, with a lenticular marble beneath the main ore body. The ore bodies occur as lamellar, stratoids and lenses, controlled by NW-, NWW-and NEE-striking faults and circular faults. Mineralizations occur along the fissures and fractures in the wall rocks. Combining the geological characteristics with the study of mineralogy, the authors hold that iron mineralization was related to skarnization, and that skarnization might have played an quite important role in the formation of the Chagangnuoer iron ore deposit.