Aim To investigate changes of serum nitric oxide(NO) in stroke-prone renovascular hypertensive rats(RHRSP) before artificicial cold.To explore the possibility of nitric oxide used as the prediction index of stroke. Methods Two-kidney,two-clip methods were used to copy the model of renovascular hypertension in rats,Serum NO levels were measured by nitrate reductase before and after artificicial cold. Results Serum NO levels in cerebral infarction group and cerebral hemorrhage group were significantly lower than that in the non-stroke group before artificicial cold;serum NO levels in cerebral infarction group and cerebral hemorrhage group after artificicial cold were significantly lower than that before artificicial cold. Conclusion Serum NO could be used as the prediction index of stroke.