Abstract： Objective To investigate the predictive value of serum aldosterone and Plasminogen activator inhibitor-1 ( PAI-1 ) levels to the severity of coronary artery lesions and the recent prognosis in acute coronary syndrome (ACS) patients underwent percutaneous coronary intervention(PCI). Methods The study included 160 consecutive patients admitted. All the patients received coronary angiography and were divided into two groups:control group and ACS group. The patients' blood samples were abtained at the root of aortic artery to measure the serum aldosterone and PAI-1 levels. We analyzed their relationship with the severity of coronary artery lesions. The patients were also divided into three groups( high-score group, moderate-score group,low-score group)according to Gensini accumulated points,we analyzed the difference of aldosterone and PAI-1 levels in three groups. The predictive values of aldosterone and PAI-1 to the recent pronosis of ACS patients underwent PCIwere assessed. Results ( 1 )The patients' serum aldosteeone and PAI-1 levels in ACS group were significantly higher than control group( all P <0. 05 ) ;(2)The aldosterone and PAI-1 levels in high-score group were higher than moderate-score group, and moderate-score group was higher than low-score group. (3)The serum aldosterone level in ACS patients was positively correlated with the PAI-1 level ( r = 0.213, all P < 0. 05 ). ( 4 ) Multiple factor Logistic regression analysis indicated that aldosterone, PAI-1 levels were srtong independent predictors for the recent prognosis of ACS patients underwent PCI. Conclusion The aldosterone ,PAI-1 levels in ACS patients were correlated with the severity of coronary artery lesions. Both of them were strong predictors for the recent prognosis of ACS patients underwent PCI.