Aim To investigate the association between polymorphism of matrix metalloproteinase 1(MMP-1) and coronary heart disease.Methods This study enrolled 35 patients with acute coronary syndrome,27 patients with stable angina(SA),31 normal volunteers.The carotid arteries were performed with echocardiography.With PCR,genotypes of MMP-1 were scored according to the patterns of DNA bands.Results The frequency of MMP-1 2G/2G type and allele T was significantly higher in ACS group than SA group and control group.The frequency of MMP-1 2G/2G type and allele T was significantly higher in fatty plaque than fibrous plaque and calcify plaque.Conclusion There was association between the acute coronary syndrome and the 2G/2G type of MMP-1.