Aim To investigate the relationship of tumor necrosis factor-α(TNF-α),matrix metalloproteinases(MMPs) and NF-κB on postmyocardial infarction progressive heart failure in rats. Methods Male rats were randomised to proximal left anterior descending branch coronary artery ligation. The rats were killed on weeks 4, 8, and 12 after ligation to examine hemodynamic parameters. Protein expression of TNF-α, MMPs gelatinlytic activity and NF-κB activity was assessed from noninfarcted myocardium, sham-operated rats were used as the control group. Results Compared with sham-operated group, the myocardial infarction rats showed significant decrease in mean arterial pressure(MAP), maximal ascending and descending velocity of the left ventricular pressure(±dp/d tmax) and significant increased in left ventricular end-diastolic pressure(LVEDP) (all p<0.05). In comparison with sham-operated group, TNF-α production was increased significantly, MMP-2 and MMP-9 zymographic activity, NF-κB activity, and collagen volume fraction(CVF) increased significantly at weeks 4, 8 and 12 after ligation in noninfarcted myocardium. Conclusions TNF-α overexpression is related to increase in MMP gelatinlytic activity and NF-κB activity, which suggests that TNF-α can play an important role in postinfarction ventricular remodeling and progressive heart failure.