Aim To investigate the clinical relevance between the matrix metalloproteinase-2 (MMP-2) and acute coronary syndrome (ACS). Methods There are 61 coronary heart disease (CHD) patients diagnosised by coronary angiography (CAG) including 46 ACS patients, 15 stable angina pectoris (SAP) patients, and 24 non-CHD patients are excluded by CAG as the control group, and 46 ACS patients are separated into 16 acute myocardial infarction (AMI) and 30 unstable angina pectoris (UAP) patients. Every sample’s serum MMP-2 levels are detected by enzyme linked immunosorbent assay (ELISA). Results Before CAG, the concentration of MMP-2 in ACS, SAP, AMI, UAP and control group was 56.9±11.9 μg/L, 48.2± 10.8 μg/L, 58.6±14.8 μg/L, 53.4±9.3 μg/L and 46.6±10.5 μg/L respectively. There are remarkable statistic difference among AMI, UAP and SAP group, and so between SAP group and control group. There was obvious correlation among the level of MMP-2 in serum and the C-reactive protein (CRP) level, white blood cell (WBC) number, pathologic coronaries’ score and pathologic stenosis’s degree, but there was no obvious correlation between the level of MMP-2 and the pathologic coronaries’ number,the level of troponin I (Tn I), MB isoenzyme of creatine kinase (CK-MB), total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDLC), low density lipoprotein cholesterol (LDLC) and the number of platelet. After percutaneous transluminal coronary angioplasty (PTCA), the level of MMP-2 is higher than that before PTCA. Conclusions The concentration of MMP-2 in ACS patients increased obviously, which was related to the stability of coronary plaque; MMP-2 contributes to type the CHD and could be the important monitering markers for CHD in clinic practices.