Objective: To determine whether hyperglycemia could aggravate the microvascular damage in ischemic stroke.Methods: Hyperglycemia model was made by injection of streptozocin through subcutaneous injection in wistar rats. Using the suture model, the rats were subjected to 3 h of focal ischemia and different times of reperfusion,including 6,12,24,48,96 h and 7 d. TTC dyeing was used to show the infarction area of rats. The infarctive volume of rats were calculated by computer imaging analysis system;Matrix metalloproteinase (MMP-2) and (MMP-9)were detected by immunohistochemistry and in situ hybridization histochemistry in Wistar rats.Results: The infarctive volume was siginificantly larger in hyperglycemic rats than that of nonhyperglycemic rats. The level of MMP-2,MMP-9 expression in the group of hyperglycemic rats was higher than that of nonhyperglycemic rats. Conclusion: Hyperglycemia aggravated the injury of focal ischmia-reperfusion in wistar rats and the higher expression of MMP-2, MMP-9 might be one of the mechanism in aggravation of focal ischemia/reperfusion injury.