Abstract: Objective To discuss the curative effects of recombinant tissue plasminogen activator combined with thrombolytic therapy in treatment of acute cerebral infarction(ACI). Methods From January,2013 to October,2015,clinical data of 75 ACI patients in our hospital were retrospectively analyzed from morbidity to give medicine<4.5 h,of which 24 patients were given medicine<3 h(Group A),30 cases were given medicine 3-4.5 h(Group B),and 21 cases were given medicine<4.5 h.And respectively in 24 h before and after treatment,7 days after treatment the NIHSS score,clinical efficacy intracranial hemorrhage and death of the three groups were evaluated. Results After treatment for 24 h and 7 d,the NIHSS scores in group A and group B were significantly lower than before treatment(t≥3.38,all P<0.05),and significantly lower than that in the control group after treatment(t≥3.42,P<0.05);After treatment for 24 h and 7 d,the NIHSS score comparison difference in group A and group B had no statistical significance(t=0.81,0.99,P<0.05).In group A and group B,7 d efficient rate was significant higher than that in the control group after treatment(χ²=11.667,11.286，P<0.05),but in group A and group B the efficient rate had no statistically significant difference(χ²=0.098,P>0.05).The mortality in group A and group B was significantly lower than that in the control group,but the death rate of group A and group B had no statistically significant difference(χ²=0.026，P>0.05).In group B intracranial hemorrhage rate was significantly higher than that in group A,which had statistically significant difference(χ²=3.881,P<0.05). Conclusions It has significant clinical efficacy by using rt-PA thrombolysis 3-4.5h and <3h after morbidity,however,the extension of time window can lead to an increased risk of intracranial hemorrhage,which doesn’t increase the risk of death;And in patients with acute cerebral infarction within 4.5h of stroke onset should be also actively given rt-PA intravenous thrombolysis treatment.