Objective To evaluate the safety of thrombolytic treatment using rt-PA at early stage of acute cerebral infarction in Chinese patients, and to analyze the significance of intra - cerebral hemorrhage after therapy. Methods 206 patients within 6 hours after the onset of stroke were divided into 3 groups: group A (thrombolytic treament using rt - PA with dosage of 0.9 mg/kg over 60 minutes) , group B (thrombolytic treatment using rt-PA with dosage of 0.7 mg/kg over 60 minutes) and group C (control group without rt-PA). Group A, group B, group C were divided into two subgroups according to using Clexane or not. Patients in subgroups A1, B1, C1 were treated with Clexane and in subgroups A2, B2, C2 were not. The Chinese Stroke Scale (CSS) and Barthel Index (BI) were used to evaluate the neurological function before and 24 hours, 3 days, 7 days, and 90 days rt-tPA. Results There was significant difference on hemorrhagic rate and cerebral hemorrhagic rate at the 48 hours and 14 days between group A, group B and group C. There was no significant difference on symptomatic cerebral hemorrhage in groups A, B and group C. There were significant differences between thrombolytic groups and group C on the effective and curative rate at 90 days after therapy. The mortality was lower in thrombolytic groups than in group C at 90 days. There was no significant difference between group A and group B , and also between the subgroups. Conclusion Thrombolytic treatment using rt-PA intravenously in patients with acute cerebral infarction within 6 hours was effective and safe. The dosage of 0.7mg/kg was suitable for Chinese patients.