Abstract: The Chaganhadamiao copper deposit in Inner Mongolia, located on the south wing of Zhesiaobao synclinorium in the Late Variscan fold belt of western Inner Mongolia-Xingan orogenic belt, is controlled by the NE-NNE-trending faults and Lower Permian Dashizhai metamorphic formation. The orebodies, occurring as Cu-bearing quartz veins, are hosted in the dacitic tuff of the third member of Lower Permian Dashizai Formation. The deposit consists of 7 copper orebodies, which generally trend to NE-NNE, with dip angles between 43° and 75°. With study on the geology of deposit, mineral composition, mineral occurrence and wallrock alteration, it is suggested that the copper mineralization should be related to the metamorphic rocks, faults and magmatic hydrothermal activities. The deposit belongs to magmatic hydrothermal type in genesis.