Objective: To investigate the correlation between cerebral infarction and the level of endothelin in the plasma. Methods: The levels of endothelin in the plasma of 68 patients and 53 normal controls were tested by ELISA. Results:The levels of endothelin in the plasma of 68 patients were significantly higher than those in 53 normal controls. Conclusion:These findings suggest that the high levels of endothelin in the plasma play a certain role in the happen of cerebral infarction.