Objective To analyze the efficacy of ultra-early intravenous thrombolysis with urokinase in acute cerebral Infractions. Methods Eighty qualified patients were randomly divided into the thrombolysis group and the control group. The thrombolysis group was given Urokinase intravenously, while the control group was treated with aspirin, combined with drugs improved circulation. Paitents' degree of neurological deficit were evaluated by China Stroke Scale(CSS) before treatment and four weeks after thrombolysis. Results CSS scores of the thrombolysis group and control group were not significantly different before treatment(P0.05) while CSS scores after treatment of two groups were significantly different (P0.01). The curative effect between two groups were statistically significant (P0.05). Conclusion The therapy of ultra-early intravenous thrombolysis with Urokinase is effective, safe and reliable in acute cerebral infraction.