Objective To investigate the effects of percutaneous coronary interventional therapy on platelet activation and the systemic fibrinolysis in patients with coronary artery disease (CAD).Methods The plasma concentration of platelet alpha granule membrane glycoprotein 140 (GMP 140), plasminogen activator inhibitor 1(PAI 1), tissue type plasminogen activator (t PA), von Willebrand factor (vWF) and D dimer (D D) of the blood sampled from vein according to the schedule were measured by ELISA. Results In the sixty five patients with CAD, at 10 minutes after the procedure, plasma levels of GMP 140, t PA and D D were significantly higher than the previous ones; and at 24 h, plasma levels of PAI 1 and vWF were also increased significantly. Conclusions The activation of platelet and impaired fibrinolytic activity were occurred after PCI in the patients with CAD.