To study the changes of matrix metalloproteinase-3 (MMP-3) and tissue inhibitor of matrix metalloproteinase-1(TIMP-1) expression during congestive heart failure.Using the reverse transcriptase-polymerase chain reaction(RT-PCR) assay, we detected MMP-3 and TIMP-1 expression in 31 patients with rheumatic heart disease (RHD) and 8 health subjects. Cardiac function parameters were measured with echocardiographs.Pathological changes of myocardial tissure in CHF with valvular heart disease showed typical myocardial remodeling. As compared with the control group, the contents of MMP-3 in RHD patients were increased significantly ( P < 0.01). The worse the cardiac function, the higher the contents of MMP-3. TIMP-1 expressions showed a reverse correlation.It is suggested that the altered expression of MMP-3 and TIMP-1 contributes to myocardial remodeling and might lead to the development and progression of congestive heart failure. These changes may induce a direct effect on the progressive deterioration of cardiac function.