Abstract: Traditionally, the Huojihe molybdenum deposit in Xiaoxinganling Mountains is classified as porphyry type. With study on its geological characteristics such as non-porphyritic mass, orebodies circling around the cryptoexplosive breccia, veinlet-network and disseminated structures of quartz and the metallogenic age obviously later than forming time of host rock, it is believed that the deposit is formed by transmagmatic mineralization. The large-super large molybdenum deposit associated with the Early Mesozoic Yichun-Yanshou granitic batholith belt is a typical product of post-batholith metallogenesis.