Abstract: Objective:To understand the difference of thrombolytic therapy for acute cerebral infarction with urokinase between various time window. Methods:9 studies, which compared the differences in effects of thrombolytic therapy for acute cerebral infarction with urokinase between various time windows, were analyzed with meta-analysis by approaches of homogeneity test and combined test. Results: （1）Homogeneity test shows that the cited studies are homogeneous with χ² =6.1274,P＞0.05;and （2）combined test shows that the combined OR= 3.0206 and its 95% confidence interval was between 1.7761～5.1371（χ²=16.6479,P＜0.001）. Conclusions: The therapeutic effects of thrombolytic therapy with urokinase within 6 hours after onset of the symptom for acute cerebral infarction is significantly superior to those after 6 hours after onset of the symptom.