OBJECTIVE：To assesss the effect of captopril on the plasma activity of t-PA and PAI-1 in rat.METHODS:Captopril was administrated at 3 different doses,to observe effects on the plasma activity of t-PA and PAI-1 in rat.RESULTS:After the treatment captopril,the plasma activity of t-PA increased significantly(P＜0.01),the plasma activity of PAI-1 and the activity ratio of PAI-1/t-PA decreased significantly(P＜0.01).This effect was in a dose-dependent manner to some extent.CONCLUSION:Captopril can activate the activity of fibrinolytic system.This effect is in a dose-dependent manner to some extent.