In the treatment based on Guided Bone Regeneration method (GBR), membranes are necessary to cover bone defects and prevent the invasion of surrounding soft tissues. In spite of the potential usefulness of GBR method, no appropriate materials for the membrane have been developed and this method is not utilized frequently in common clinical practice. Here we developed materials such as a composite of β-tricalcium phosphate (β-TCP) and copolymer of L-lactide, glycolide and ε-caplolactone (PLGC), and designed the novel GBR membranes with ideal mechanical properties. The materials had good biocompatibility, and the membrane had sufficient strength although their thickness was as thin as 200 μm. The membranes were applied to large bone defects created in canine mandibular bones, and significant enhancement in bone regeneration was demonstrated.