〔Abstract〕 Objective To explore the mechanism of positive Hoffman sign in patients with cervical spondylosis myelopathy(CSM). Methods DTI analysis was performed in 88 patients with CSM(50 positive and 38 negative with Hoffman sign) and 30 healthy controls. In the high cervical spinal cord level(C1-C3), the reticular spinal tract, thin wedge tract, anterior corticospinal tract and lateral tract were selected as the regions of interest, and it was analyzed whether the DTI parameters of different conduction tract areas within and between groups were statistically significant. Results There was a significant difference in the ratio of DTI parameters in different conduction tract areas of the high cervical spinal cord in patients with CSM. Compared with the Hoffman sign negative group and the healthy control group, the Hoffman sign positive group showed lower FA ratio and higher ADC ratio in the corticospinal tract area(P<0.05). Conclusion The occurrence of Hoffman sign is related to the damage of corticospinal tract. For CSM patients with positive Hoffman sign, the microstructural damage of the spinal cord has occurred at the high level of the cervical spinal cord far from the lesion.