Objective To detect the effect of erigeron breviscapus on the expression of vascular endothelial growth factor（VEGF） in the periodontal tissues during
orthodontic tooth movement. Methods 45 rabbits were divided into 3 groups（groups A, B and C）. Groups A and B included experimental group of 1, 3, 7 and 14 days respectively. The mandibular first molar of each experimental rabbit was observed. The rabbits of group A and group B received iontophoresis with erigeron breviscapus into the right（group A-R and group B-R） and with normal sodium into the left as the control（group A-L and group B-L）. Additionally, the rabbits of group B were designed orthodontic appliance, by which 0.78 N mesial force was applied to pull the mandibular first molars. Group C, group of 0 day, was no iontophoresis and orthodontic appliance as the control. After killed on schedule, the amount of experimental tooth movement was measured and the expression of VEGF was examined by immunohistochemical method. Results The amount of experimental tooth movement increased successively from 1 to 14 days. The differences among days 3, 7 and 14 were significant in the comparison between group B-R and group B-L（PVEGF in groups A-R and B-L enhanced apparently compared with that in groups C and A-L（P
accelerate orthodontic tooth movemen is erigeron breviscapus effects the metabolism and differentiation of osteoblast and osteoclast through up-regulating the
expression of VEGF in periodontium.
