Bone remodeling is essential for successful orthodontics treatments. This study investigates the effect of 940 nm low level laser with different powers on orthodontic tooth movement in rats. 21 male, 6-week-old Sprague Dawley rats were used. A force of 10g was applied to the molars to induce tooth movement. The rats were grouped into 3 main experimental groups according to the power delivered: 100, 200 and 300 mW for 6 min/day. A positive and negative control groups were used. The Irradiation was performed once a day on days 0-7, then the experiment was ended in the same day. To determine the amount of tooth movement, plaster models of the maxillae were made. The models were imaged and analysed. Histological examination was performed after staining with (haematoxylin and eosin) and (Alizarin red and Alcian blue) stain. RT-PCR was also performed to elucidate the gene expression of RANK, RANKL, OPG and RUNX-2 in the area of treatment. The amount of tooth movement, the Histological bone remodelling and the RT-PCR was significantly greater in the treatment groups than that in the control group. Among the treatment groups, the 100 mW group was the highest and the 300 mW group was the lowest. These findings suggest that 940 nm low level laser treatment can facilitate the velocity of tooth movement and improve the quality of bone remodelling during orthodontic tooth movement in rats.