Aim To explore the effect of percutaneous coronary intervention on the expression of matrix metalloproteinase-2 in the patients with coronary heart disease. Methods Fifty patients with coronary heart disease were selected. There were 25 cases undergoing percutaneous coronary intervention and 25 cases undergoing coronary angiography and bypass graft surgery. Venous blood samples were obtained before and after coronary angiography or 1 day before and l, 10, 30 days after percutaneous coronary intervention. Plasma concentrations of matrix metalloproteinase-2 were determined by enzyme linked immunoassay. Results There were no significant differences in matrix metalloproteinase-2 concentrations of coronary angiography group at each time point (P>0.05). The concentrations of matrix metalloproteinase-2 were significantly increased on days 1, 10, and 30 after percutaneous coronary intervention, and those on day 10 were higher than on 1 day (P<0.05), and on 30 day were higher than on 10 day (P<0.01). The concentrations of matrix metalloproteinase-2 in patients of type B were significantly higher than in patients of type A (P<0.05), and in patients of type C were higher than in patients of type B (P<0.05). The concentrations of matrix metalloproteinase-2 in patients with two diseased vessels were significantly higher than in patients with single diseased vessel (P<0.05), and in patients with three diseased vessels were higher than in patients with two diseased vessels (P<0.05). Conclusions Coronary angiography does not influence matrix metalloproteinase-2 expressions. Stent implantation can lead to increases in matrix metalloproteinase-2. The increases of matrix metalloproteinase-2 are correlated to the degree of coronary stenosis.