This study was performed to evaluate the effect of freeze-dried bone graft on space-making capacity and bone formation in the procedure of guided bone regeneration with titanium reinforced ePTFE membrane. After decortication in the calvaria, GBR procedure was performed on 8 rabbits with titanium reinforced ePTFE membrane filled with human FDBA(Rocky Mountain Tissue Bank,Aurora Co., USA). Decortication was performed to induce the effect of bone forming factor from bone marrow. The animals were sacrificed at 2 weeks, 4 weeks, 8 weeks and 12 weeks after the surgery. Non-decalcified specimens were processed for histologic analysis. πle results of this study were as follows: 1. Titanium reinforced-ePTFE membrane was biocompatable and capable of maintaining the space-making. 2. FDBA particle was surrounded with connective tissues but there was no evidence on new bone formation. 3. FDBA particle resorbed continuously but it remained until 12weeks after the surgery. Within the above results, TR-ePTFE membrane could be used effectively for Guided bone regeneration but It was assumed that FDBA does not appear to contribute to bone formation.