Abstract: Abstract：Located on the edge of the metamorphic belt formed by paleo-Kumishi ocean subduction, the Baoertu copper deposit is controlled by fault structures. The wall rocks are composed of a set of medium-deep grade metamorphic rocks, and REE geochemistry shows that their ΣREE content is high, with LREE/HREE being 2.46～16.86, and there exists obvious differentiation between LREE and HREE, with the enrichment of LREE relative to HREE and the existence of negative Eu anomaly. The REE patterns assume right inclination. By comparison, the ores have relatively low ΣREE content, with LREE/HREE being 0.06～0.97, and show significant differentiation between LREE and HREE characterized by relative enrichment of HREE. The REE patterns show left inclination, similar to things of the leucosome of migmatite. These REE characteristics suggest that the ore-forming process of the Baoertu copper deposit was related to hybirdization. Combined with the characteristics of the ore field geology, this paper holds that the Baoertu copper deposit is genetically of the metamorphic hydrothermal type.