Objective: To observe the effect of endothelin receptor antagonist on blood flow and function of injuried spinal cord in rats and explore mechanisms of ET in spinal cord injury (SCI). Methods: The thoracic spinal cord of rats was compressed by a load of 35 g for 5 min, which caused moderate injury. The rats were assigned into 3 groups: control group, injuried group, PD142893 group. The changes of spinal cord blood flow (SCBF) were measured by way of Laser Doppler flowmetry during 8 hours and the neurological function of injuried rats was evaluated one week after spinal cord injury. Results: PD142893 significantly increased early SCBF at compression sites after SCI by intrathecal injection and partly restored the motor function of the damaged spinal cord. Conclusion: ET plays a key role in secondary injury after acute spinal cord injury and that intrathecal injection of ET receptor antagonist PD142893 can partly reverse the progression of SCI.