Abstract: Objective: To study the efficiency of vascularized bone graft combined with reconstituted bone xeno graft(RBX) in repairing the bone defection and the expression of the vascular endothelial growth factor(VEGF) as an evaluation index of bone graft success.Methods: Twenty-seven cases of bone defection were randomly divided into vascularized bone graft-RBX group,vascularized bone graft group and RBX group.The clinical results were evaluated by the radiograph 3 months,6 months and 12 months after operation according to whether the bone defection was repaired,how long it took the bone to heal and whether the bone graft died away or not.The expression of VEGF in serum was assayed with immuno analysis method in the 3 groups 2 weeks,4 weeks,6 weeks and 8 weeks before and after the operation.Results: The bone defections were repaired in 8 cases,6 cases and 3 cases in the vascularized bone graft-RBX group,vascularized bone graft group and RBX group,respectively,3 months after the operation.One case,3 cases and 3 cases of bone defections in the vascularized bone graft-RBX group,vascularized bone graft group and RBX group achieved delayed recovery respectively 6 months after the operation.One case in the vascularized bone graft group and 2 cases in the RBX group developed part absorption in the bone transplantation area 12 months after the operation.The difference was not significant(P>0.05).Serum VEGF value was higher 2 weeks and 4 weeks after the operation than before the operation in all the 3 groups,which was more obvious with the vascularized bone graft-RBX group and vascularized bone graft group (P<0.01).The serum VEGF value 6 weeks and 8 weeks after the operation had no significant difference between the groups(P>0.05).Conclusions: Vascularized bone graft-RBX is more effective compared to the other 2 methods in repairing bone defections.After the operation,serum VEGF value in the vaschlarized bone graft-RBX group and the vascularized bone graft group increased,compared with that of the RBX group.The expression of serum VEGF increased obviously in the earlier period of bone transplantation.It is of value for clinical evaluation of the efficiency of bone defection repair with bone graft.