Metal organic framework (MOF) membranes have attracted considerable attention because of their striking advantages in small molecule separation. The preparation of an integrated MOF membrane is still a major challenge. Depositing a uniform seed layer on a support for secondary growth is a main route to obtaining an integrated MOF membrane. A novel seeding method to prepare HKUST-1 (known as Cu-3(btc)(2)) membranes on porous alpha-alumina supports is reported. The in situ production of the seed layer was realized in step-by-step fashion via the coordination of H(3)btc and Cu2+ on an alpha-alumina support. The formation process of the seed layer was observed by ultraviolet visible absorption spectroscopy and atomic force microscopy. An integrated HKUST-1 membrane could be synthesized by the secondary hydrothermal growth on the seeded support. The gas permeation performance of the membrane was evaluated.