Aim To explore the dynamic changes of the plasmatic activities of tPA and PAI-1 and its clinical significance by observing the plasmatic activity of tPA and PAI-1 in acute and recovery phases of the patients with arteriosclerotic cerebral infarction (ACI). Methods The plasmatic activities of tPA and PAI-1 were determined by Chromgenic Substrate methods in 91 patients with ACI and 40 normal old ages as control, while the infarction volume and the neurological damage score in those with ACI were measured. Results The plasmatic activities of tPA in acute and recovery periods of the patients with ACI was 0.26±0.14and0.21±0.11 kIU/L respectively and was significantly lower than those of the control subjects ( P< 0.01), and the plasmatic activities of PAI-1 in acute and recovery periods of the patients with ACI were 0.90 ± 0.25 and 0.98 ± 0.12 kAU/ L respectively and were significantly higher than those of the control subjects ( P< 0.01), while the infarction volume and the neurological damage score in those with ACI were 8.75 ± 1.21 cm and 18.56 ± 3.62 respectively, and the plasmatic activity of tPA was negatively related to the infarction volume and the neurological damage score in those with ACI (r = - 0.5133, P< 0. 05 and r = - 0.4914, P< 0.05 respectively ), and the plasmatic activity of PAI-1 was positively related to the infarction volume and the neurological damage score in those with ACI(r = 0.5621, p< 0.05 and r = 0.5342, p< 0.05 respectively). Conclusions The fibrinolysis activities of the acute and recovery periods of the patients with ACI decline significantly, which suggests that tPA and PAI-1 play an important role in the pathological process of arteriosclerotic cerebral infarction.