Based on petrochemistry, fluid inclusion, strontium isotopic tracer and previous discussion. this paper further verified the possibility of ore-forming material transportation-congregation-mineralization decided by the nature of the Tongchang porphyry intrusive. It is indicated that the massive hydrothermal fluids could release from convecting magma columns emplaced at small depths. Ore-forming materials such as copper were transferred from parent magma by high salin-ty magmatic hydrothermal fluids to flow upward and along the contact with the wall rocks, and then to form ore deposits along the contact and in the shallow portion of the porphyry cupola. Further studies supported the orthomagmatic genesis for Dexing porphyry copper deposit.