Abstract: The Weilasituo Zn-Cu polymetal deposit in Inner Mongolia, occurred in the Paleoproterozoic Baoyintu formation and the Middle Variscan granodiorite body, is controlled by the E-W-trending compresso-shear fault on the southeast wing of the Mishengmiao anticlinorium. With study on the geology of orefield and orebody, the structure of ore, the mineralogy, wallrock alteration and chemical composition, it is concluded that the metallogenesis of the Zn-Cu polymetal deposit is closely related to the quartz diorite intrusion. The deposit is formed in Middle Variscan, genetically belonging to magmatic hydrothermal type.