Abstract: Objective To compare the immunoreaction of cyclosporine-impregnated allograft bone（CAB） and freeze-dried allograft bone（FDAB）. Methods Sixty New Zealand white rabbits were divided into bone donor group,experimental group,and control group（20 in each group）.CAB and FDAB were prepared with the bilateral iliac bone from donor group.A 10 mm long bone defect in the right radius middle segment in experimental group and control group was repaired with CAB and FDAB,respectively.Serum and bone at the defect site IL-2 and TNF-αlevels were measured in 5 animals of each group at weeks 2,4,8 and 12 after operation. Results There were no significant difference in serum IL-2 and TNF-αlevels between two groups at weeks 2,4,8,12 after operation.The bone at the defect site IL-2 and TNF-αlevels were significantly lower in experimental group than in control group at 2 and 4 weeks after operation（P＜0.05）.However,no significant difference was found in bone at the defect site IL-2 and TNF-αlevels between the two groups at 8 and 12 weeks after operation（P＞0.05）. Conclusion CAB does not result in general immunoreaction.Its local immune rejection is weaker than FDAB.