Abstract: Objective:To observe the change of coagulation-related indicators levels(fibrinogen,fibrin degradationproductsand D-dimer)of different doses of recombinant tissue plasmiogen activator(rt-PA)in the treatment of acute cerebral infarction in middle cerebral artery zone.Methods:Eighty patients with acute cerebral infarction were treated with intravenous thrombolysis after 7 hours,and randomly divided into rt-PA 0.8 mg/kg and rt-PA 0.9 mg/kg group(40 cases each group).The levels of coagulation-related indicators(including fibrinogen,fibrin degradation products,D-dimer,clotting factor ⅩⅢ,2-antiplasmin plasminogen and platelet)in two groups were observed at 2 hours before thrombolysis and at 2 and 24 hours after thrombolysis.Results:The level differences of fibrinogen,fibrin degradation products,D-dimer,clotting factor Ⅲ,2-antiplasmin,plasminogen and platelet in two groups were not statistical significance(P0.05).Conclusions:There is no evident difference in the coagulation-related indicators between two groups,the 0.8 mg/kg can be selected to treat acute cerebral infarction.