Abstract: Nenjiang-Heihe area is located in the northeastern segment of the eastern Ujimqin Banner-Nenjiang metallogenic belt in Great Khingan Range, and it constitutes an important Cu-Au production base in Heilongjiang Province. A series of achievements have been obtained in geological prospecting in recent years, nevertheless, the relationship between ore-controlling structures and mineralization remains unclear. Based on regional geological setting, geological features of deposits and isotopic geochemistry, the authors in this study analyzed the mineralization types and mineralization processes, and discussed future prospecting directions. The results showed that Duobaoshan island-arc belt was predominantly characterized by porphyry Cu deposit, which experienced mineralization mainly in the Early Ordovician and superimposed mineralization structure in the Late Ordovician. Kolo-Xinkailing tectonic mélange belt hosted ductile shear-zone-type and epithermal-type Au deposits, which formed mainly in the Early Cretaceous. S and Pb isotope data revealed that ore-forming materials of porphyry Cu deposits in Duobaoshan island-arc belt were predominantly mantle-derived, whereas the Au deposits in Kolo-Xinkailing mélange belt exhibited crust-mantle mixed sources. Fluid-inclusion characteristics showed that ore-forming fluids in Duobaoshan belt featured wide ranges of temperature and salinity, high CO₂ contents, and local reduction signals in the late stage. Significant fluid-boiling occurred in the main metallogenic stage of the porphyry copper deposit. The ore-forming fluids in Kolo-Xinkailing tectonic mélange belt were characterized by low temperature, low salinity and low density. H-O isotopes suggested that ore-forming fluids of porphyry-type Cu deposits exhibited magmatic-hydrothermal characteristics with intensive water-rock interactions under high-temperature conditions, and the ore-forming fluids of epithermal Au deposits were dominated by meteoric water. Three key metallogenic episodes were recognized in Nenjiang-Heihe area. The first episode was the Ordovician Cu-Au mineralization related to the subduction of the Paleo-Asian Ocean. The second episode was the Triassic Cu-Au mineralization associated with the subduction and closure of Mongol-Okhotsk Ocean. The third episode was the Early Cretaceous Au mineralization triggered by the closure of Mongol-Okhotsk Ocean together with subduction roll-back of the Paleo-Pacific Ocean. These understandings have improved the Cu-Au metallogenic mechanism under the background of multi-tectonic domain superposition in the northern Great Khingan Range, and could provide important theoretical basis for target optimization and exploration deployment of Cu-Au deposits in Nenjiang-Heihe area.