Existing genetic models for porphyry copper deposits are based on B-type subduction. The Indian plate came into collision with the Asian plate 65 Ma ago. Ore-formation for the Gangdise porphyry copper deposits took place during 18 Ma to 12 Ma when early subduction of the Indian continental crust beneath the Asian continental crust occurred. Such a subduction belongs to A-type subduction. Then, Tethyan oceanic crust between the Indian continental crust and the Asian continental crust still existed. Thus, dehydration and partial melting of the upper mantle provided ore matter for the Gangdis6 porphyry copper deposits. This paper deals with relationship between plate subduction and ore-formation of porphyry copper deposits and ore matter sources for the Gangdise porphyry copper deposits based on Nd. Sr isotope compositions for the Qulong and Chongjiang porphyry copper deposits. A genetic model for the Gangdise porphyry copper deposits is advanced on the basis of ore zone structure and ore-forming ages.