Abstract: Objective To detect the effect of stem cell factor (SCF) combined with PluronicF127 gel on the directional migration of bone marrow mesenchymal stem cells (BMSCs),then investigate the effect on healing after repair of mandibular defects in rats.Methods ①Transwell chamber was used to observe the migration of BMSCs in SCF gel group and blank control group.Count the number of migrated cells.②Bone defects 3 mm in diameter were established in 30 clean SD rats′ bilateral mandibles,on the right sides of which composite material was injected,while the left sides of which served as control group.6 rats were sacrificed separately in the 1st,2nd,4th,6th,8th weeks after surgery.The mandibles were taken out and the bilateral bone defects were observed by Xray.The specimens were fixed,sliced and dealt with histochemical staining of alkaline phosphatase(ALP) and CD34 separately.The staining was scored.The growth of new vessels was counted.T test was used to analyze and judge the results.Results For bone marrow mesenchymal stem cells cultured in vitro,chemotaxis assay showed that number of migrated cells in SCF gel group was more than that in blank control group（P<0.05）.Composite material in the wound of rats was gradually absorbed 18 weeks after mandibular surgery.Scores of ALP immunohistochemical staining in SCF gel group was higher than that in blank control group after surgery（P<0.05）.Number of new vessels in experimental group was more than that in control group 12 weeks after surgery（P<0.05）,while two groups had no significant difference in number of new vessels during 48 weeks （P>0.05）.Conclusions Composite SCFgel can migrate BMSCs to certain degree.Furthermore,it can promote new vessels′ growth and new bones′ formation and accelerate healing process of orthopaedic injuries in vivo which are larger than selfhealing bone defects.