Disclosed is a method for producing a collagen/apatite composite membrane useful as a barrier to protect fibrous connective tissues from infiltrating into a site of defective tissue or bone in guided tissue regeneration (GTR) or guided bone regeneration (GBR) procedures. Such composite membrane can be obtained by the steps of co-precipitating collagen and apatite in aqueous basic solution in a very well controlled manner, followed by casting the precipitation onto a filter paper, lyophilization and cross-linking. The method according to the present invention can allow forming a collagen/apatite composite membrane in which the crystals of apatite, in particular, hydroxyapatite are coated on and along with the collagen fiber direction without aggregation of self-assembled collagen fibers. Such composite membrane has excellent biological and mechanical properties such as biocompatibility, cell affinity, biodegradability and form stability, and therefore it can be used as a barrier for GTR. The method of the present invention can also allow the composite membrane to have microstructure enabling osteoblasts to be attached and proliferated well on the membrane, and can allow the properties of membrane to be controlled by adjusting its thickness in the formation of membrane, thereby providing a collagen/apatite composite membrane suitable to a needed use.
