Objective To study the possible repair mechanism of Shangke Jiegu Tablets（bone-setting tablets）for mandibular defect.Methods Totally 72healthy male New Zealand rabbits were randomized into the normal control group

model control group and Shangke Jiegu Tablets group

with 24in each.The mandibular defect models were established in all groups except the normal control group.The normal control group and model control group were given 40g/d normal forage.The Shangke Jiegu Tablets group was given 40g/d Shangke Jiegu Tablets forage（containing about 0.528g Shangke Jiegu Tablets）.Six rabbits in each group were sacrificed on the 7th

14th

28th and 56th day after modeling respectively.The bone tissue in mandibular defect area was collected after mandible X-ray examination.The protein and mRNA expression of Cyclooxygenase-2（COX-2）and the positive dyeing strength and area of bone tissue were detected.Results Comparing with the normal control group

the protein and mRNA expression of COX-2increased significantly on the 14th and 28th day after modeling in the model control group（P<0.05）.Comparing with the model control group

the protein and mRNA expression of COX-2increased significantly on the 14th

28th and 56th day after modeling in the Shangke Jiegu Tablets group（P<0.05）.Imageology showed that the speed of bone-formation was faster and the density of new bone was greater in mandibular defect area in the Shangke Jiegu Tablets group.Conclusion Shangke Jiegu Tablets can repair the mandibular defect by up-regulating the protein and mRNA expression of COX-2.