Abstract: To explore the plasma levels of MMP-9, M-SCF and CRP of patients with ACS and SA before and after percutaneous coronary intervention, so as to quantify the relation between structural characteristics of plaque and plasma levels of MMP-9, M-SCF and CRP. Methods35 patients with acute coronary syndrome and 27 patients with stable angina were enrolled in this study. Serum MMP-9, M-SCF and CRP levels were determined by the speed diffused light turbidimetric method and by enzyme association immunity adsorption law before and after percutaneous coronary intervention. Based on coronary angiography plaque morphology, the patch was typed as Ⅰ, Ⅱ and Ⅲ and based on ultrasound for the carotid artery, plaque was typed as stable and unstable plaques. Results ① Serum MMP-9, M-SCF and CRP levels were significantly higher in the ACS group than those in the SA group（P＜0.05). ② MMP-9, M-SCF and CRP levels were significantly different in the ACS and SA patients before and after intervention treatments（P＜0.05). ③ The majority of the coronary plaque of the ACS group was type Ⅱ and of the carotid artery plaque was vulnerable, which were significantly different from those of the SA group（P＜0.05). Conclusion Levels of MMP-9, M-SCF and CRP are related to plaque structural characteristics and plaque stability.

Key words: Matrix metalloproteinase-9, Percutaneous transluminal coronary angioplasty, Stent implantation, Atherosclerosis, C-reactive protein, Macrophage colonystimulating factor