Abstract: Objective: To observe the remodeling of alveolar bone in rats with the vertical absorption after loading orthodontic force, and to provide evidence for clinical orthodontic treatment. Methods: 75 SD rats (10-week-old ,male)were randomly divided into three groups(25 in each group):loading force control group (A), control group of periodontitis with vertical bone absorption (B), loading force group to periodontitis with vertical bone absorption (C).With loading force on for 8 hours, 1d,7d, 14d and 21d,the alveolar bone of the first molar of left maxillary were taken to do the histological and immunological detection. Results: On the7th day, the derange of the periodontal ligament fibers, non-cellular structure, a small amount of inflammatory cells,and active multinucleated osteoclasts were observed. There was no significant difference between the control groups and experimental group in histological detect. But the IGF-1 peak was detected on the 7th day in experimental group(C),much higher than that in the control groups(P<0.05).On the 14th day, the RUNX2 peak was detected in the experimental group(C), and much higher than that in the control groups(P<0.05).Conclusions: After controlling periodontal disease and eliminating occlusal trauma, loading orthodontic force which could enhancethe of RUNX2 and IGF-1in alveolar bone defect region, and also the capacity of remodeling of bone matrix and collagen, contribute to tooth alveolar bone remodeling.