Abstract: The Aolunhua porphyry copper-molybdenum deposit is located in the north of the Xilamulun flault in the southern area of Da Hinggan Mts. The diposit occurs in the granite porphyry and felsic hornfels. The dike in the ore district is very development and forms later than the granite porphyry and Cu-Mo mineralization. Major elements of the host granite porphyry are high Si、Al、Na content, low Ca、Mg and Fe2O3T content, and A/CNK＜1.1. The REE and trace elements display a typical characteristics of adakite evidenced by slight negative Eu anomaly, intensive REE fractionation with LREE/HREE ratio of 11.43～18.33 and the LaN/YbN ratio of 14.64～37.55; The characteristics of high Sr（＞400×10-6）, low Y（≤18×10-6）and Yb（≤1.9×10-6） probably indicate a post-collisional tectonic setting. The geochemical characteristics of quartz diorite-porphyrite suggest that it may share a same source with host granite porphyry. The rhyolite porphyry characterized by low Sr, high Y and Yb，and obvious negative Eu anomaly, may represents a tensional environment and different magmatic source from the host granite porphyry. Based on the geochemistry and tectonic setting of the host granite porphyry. It is considered that the Aolunhua copper-molybdenum deposit has favorable ore-forming conditions and prospecting potential.