Abstract: AIM: To investigate the expression of Cdh1 in the sensorimotor cortical of rats after spinal cord injury and to study the repairing effect of silencing the expression of Cdh1 by lentivirusmediated RNAi. METHODS: Fifteen male Sprague-Dawley rats were randomly divided into normal group and operation group. The injury models in the operation group were made with Allen method(T10-T11) and the expression of Cdh1 in the sensorimotor cortical was examined by quantitive real-time PCR. Another 30 male Sprague-Dawley rats were divided into group A, group B and group C. At 7 d after surgery, the rats of the 3 groups received injection respectively of normal saline, lentivirus vector and recombinant lentivirus. The behavior was evaluated with BassoBeattie-Bresnahan(BBB) every week. Ten days after injection, the expression of Cdh1 was examined by quantitive real-time PCR. Six weeks after injury, the animals received injection of BDA-TR and at 8 weeks, fresh frozen sections were prepared from the spinal cord tissue. RESULTS: The expression of Cdh1 mRNA in operation group was significantly higher than that in normal group (P<0.05). The expression of Cdh1 mRNA in group C was lower than that in group A or group B 10 d after injection(P<0.05). Six weeks after injury, the BBB assessment in group C was higher than that in group A or group B (P<0.05) and more nerve fibers were observed extending past the lesion in group C. CONCLUSION: APC-Cdh1 may play an important role in inhibiting the axonal growth.