OBJECTIVE： To explore the prognosis effect of Shengmai injection to the rt-PA thrombolysis on broadened therapeutic window patients of mild-to-moderate cerebral infarction under the guidance of computer tomography（CT）. METHODS： 168 patients with mild-to-moderate cerebral infarction were randomly divided into control group （84 cases） and observation group （84 cases）. Control group received rt-PA （0.9 mg/kg）， and 10％ of the total rt-PA was mixed and injected into patients within 1 min， the rest 90％ adding into 250 ml 0.9％ Sodium chloride injection （no less than 1 h）， CT was performed after 24 h thrombolytic therapy， and the patients with no intracerebral hemorrhage in re-examination received 300 mg/d aspirin for 10 d， then 100 mg/d for 90 d， and appropriate statins， calcium antagonists， β-blockers and nitrates； observation group additionally received 40 ml Shengmai injection， adding into 250 ml 5％ Glucose injection， intravenous infusion， once a day， for 28 d. National Institutes of Health Stroke Scale （NIHSS） score， Rankin score， daily living-Barthel Index （Barthel） score， rate of symptomatic intracranial hemorrhage， rate of secondary hemorrhage， hospitalization time， 3-month postoperative mortality and incidence of adverse reactions in 2 groups were observed. RESULTS： Before treatment， there were no significant differences in the NIHSS score， Rankin score and Barthel score （P＞0.05）. The NIHSS score in 2 groups after 6 h， 24 h and 7 d were significantly lower than before， and observation group was lower than control group after 24 h and 7 d；Rankin score after 3 months was significantly lower than before， and observation group was lower than control group； Barthel score after 3 months was significantly higher than before， and observation group was higher than control group， The differences were statistically significant （P＜0.05）. The hospitalization time in observation group was significantly shorter than in control group， and 3-month postoperative mortality was significantly lower than control group， the differences were statistically significant （P＜0.05）. There were no obvious adverse reactions during treatment. CONCLUSIONS： Based on conventional treatment， Shengmai injection has improvement in the rt-PA intravenous thrombolysis on broadened therapeutic window patients of mild-to-moderate cerebral infarction under the guidance of CT， it can reduce NIHSS score and Rankin score， increase Barthel score， shorten hospitalization time and reduce the 3-month postoperative mortality， with good safety.