The Huoluotai Cu（Mo）Deposit, a newly discovered porphyry‑type copper deposit in the northernGreater Khingan Mountains, remains understudied with respect to its main metal sulfides（pyrite and chalcopyrite）which restricts understanding of its ore‑forming environment and genesis. This study focuses on the geochemicalcharacteristics of pyrite and chalcopyrite within the deposit, based on electron probe analysis. The results show thatarsenic（As）and nickel（Ni）in pyrite likely occur as mineral inclusions, while cobalt（Co）and molybdenum（Mo）may be present in isomorphic substitution. In chalcopyrite, zinc（Zn）and Mo may also occur as mineral inclusions,while As and Co are possibly present in isomorphic substitution. Both pyrite and chalcopyrite generally show Fe‑ andS‑deficient characteristics compared with their theoretical compositions. The w（S）/w（Fe）ratio of pyrite ranges from1.181 to 1.216, exceeding 1.148, indicating formation under relatively high sulfur fugacity conditions. The average value of[n（Cu）+n（Fe）]/n（S）in chalcopyrite is 0.941, suggesting a formation temperature close to 200 °C, which implies thatchalcopyrite and associated metal sulfides were likely precipitated from a medium‑temperature hydrothermal system. TheδFe and δS values of pyrite range from −0.095 to −0.050 and −0.044 to −0.007, respectively, and the w（S）/w（Se）ratioranges from 0.128 × 10⁴ to 0.241 × 10⁴, indicating a magmatic hydrothermal origin.