Abstract: Objective To find an objective and accurate examination for evaluation of spinal cord injury （SCI） in forensic clinical medicine. Methods The onset latency of cortex, peak latency of N1, central motor conduction time （CMCT） and wave width of the abductor pollicis brevis and the anterior tibialis were calculated by transcranial magnetic stimulation-motor evoked potential （TMS-MEP）. The data of 68 patients suffered from SCI including 23 cervical levels and 45 thoracolumbar levels were collected and compared with that of 30 normal controls. Results In experimental group, when the muscle strength of the abductor pollicis brevis or the anterior tibialis decreased or disappeared, the onset latency of cortex, the peak latency of N1, and CMCT prolonged and the wave width broadened. And these indexes of grade 2 and 3 muscle strength in experimental group were higher than that in the control group （P<0.05）. Conclusion The TMS-MEP can determine directly and objectively the motor functional status of pyramidal tract of spinal cord in order to provide more accurate and objective evidences in forensic medicine.

Key words: forensic medicine, spinal cord injury, evoked potentials, motor, transcranial magnetic stimulation