Aim To explore the efficacy of defibrase in treatment of acute cerebral infarction and the effect of hemorheology. Methods 100 cases with acute cerebra infarction were randomly allocated to two groups: 50 cases in treatment group were given intravenous infusion of defibrase 10 u every other day for 3 times, and 50 cases in control group were given Co-Danshen 20 mL every day for 7 days. Then before and after treatment in 14 days, two groups were observed in time of taking effect, curative effect, side effect and hemorheological change respectively. Results The total effective rate of the treatment group was 90%, which was significantly higher than that of the control group (68%) (p<0.05), and the time taking effect was earlier (p<0.01). At the same time, indexes of hemorheology were remarkably declined (p<0.01 or p<0.05). There was only 1 case that came about bleeding cerebral infarction. Conclusion Defibrase is efficacious, safe and rapid for the treatment of Acute Cerebra Infarction.