Abstract: Objective To investigate the effects of repetitive transcraniai magnetic stimulation (rTMS) on rats with acute spinal cord injury (SCI). Methods Twenty-four SD rats were equally randomized into normal group, SCI control group, high-frequency rTMS group and low-frequency rTMS group (n=6). T10 spinal cord injury models were induced by weight-drop device. Twenty- four h after the success of model making, high-frequency rTMS group received 10 Hz threshold rTMS and low-frequency rTMS group received 1 Hz threshold rTMS once daily for a consecutive 4 w. SCI control group received sham stimulation. The scores of Basso Beatti and Bresnahan (BBB) locomotor rating scale were recorded 1, 3, 7,11, 14, 21 and 28 d after the success of model making. Motor evoked potential (MEP) was detected on the 14th and 28th d of injury. HE staining was employed to detect the changes of histomorphology and neurofilament (NF-200) protein was detected with immunofluorescence staining in the spinal cord injury lesion. Results The BBB scores in stimulation groups were significantly higher as compared with those in the SCI control groups (P<0.05); those in the high-frequency rTMS group were statistically higher than those in the low-frequency rTMS group(P<0.05). The MEP was shorter in the stimulation groups as compared with that in the other 2 groups (P0.05); that in the high-frequency rTMS group was statistically shorter than that in the low-frequency rTMS group (P<0.05). NF-200markers in the stimulation groups were significantly increased compared with those in the SCI control group (P<0.05); those in the high-frequency rTMS group were statistically higher than those in the low-frequency rTMS group (F<0.05). Conclusion The rTMS can improve the locomotor function of rats with spinal cord injury, resulting from the increased expression of NF-200. The obvious effects in the high-frequency rTMS group might relate to the regulation of cortex excitability.