Objective:The purpose of this study was to investigate the effects of low power laser on basic fibroblast growth factors (bFGF) expression in periodontal tissue during tooth movement.Methods:18 white rabbits were randomly divided into 6 groups with 3 rabbits in each group, including groups of l, 3, 5, 7, 14 and 21days. Under an anesthesia condition by 2% pentobarbital sodium, the stainless coil springswere fixed between the firstmaxillary molar and the incisorproducing the force of 80 g. The right side of maxilla was considered as the experimental group under the irradiation of low power laser with the left side as the control groups. The expression of bFGF was investigated half-quantitatively through immunohistochemical analysis.Results:The expres- sion of bFGF in periodontal tissue with irradiation of lowpower laserwas higherthan the control side. There were significantdiffer- ences among the 5, 7, and 14 day groups. In the tension area of the experimental side, the expression of bFGF in the osteoblastic surface of alveolarbone was characteristically greaterthan thatof the control side.Conclusion:The laserof lowpowerpromotes the expression of bFGF in the periodontal tissue and alveolar bone remodeling.