Aim To determine whether left ventricular remodeling with or without onset heart failure after myocardial infarction is associated with the regional changes in the gene expression of fatty acid metabolism. Methods Myocardial infarction(MI) was induced in rats by ligation of the left anterior descending coronary artery. Hemodyanmics, ventricular remodeling parameters were investigated in the experimental and sham operated animals(SH) at 2, 4, 8 week after operation. In infarcted hearts, the peri infarction region(4 mm zone surrounding the region) were separated for gene expression analysis of the rate limiting enzyme[muscle carnitine palmitoyltransferase I (M CPT I)], key enzyme[medium chain Acyl CoA dehydrogenase(MCAD)] of fatty acid oxidation and nuclear transcription factor [peroxisome proliferator activated receptors α(PPAR α)]. Results At 2 weeks after LAD ligation, when right ventricular hypertrophy was present without signs of heart failure, mRNA expression of M CPT I, MCAD and PPAR α was reduced in the peri infarction regions[27%,35%and 20% respectively in MI 2w vs SH; ([WTBX]p<0.05)]. Until 8 weeks, left ventricle displayed a little hypertrophy with heart failure, there was significant downregulation in mRNA expression of M CPT I, MCAD and PPAR α in the peri infarction regions . Until 8 weeks, left ventricle displayed a little hypertrophy with heart failure, there was significant downregulation in mRNA expression of M CPT I, MCAD and PPAR α in the peri infarction regions [reduced 52%,60% and 44% respectively in MI 8w /SH 8w vs MI 2w /SH 2w ;([WTBX]p<0.05)]. . Conclusion In rats with MI, progression from compensated remodeling to heart failure is associated with gene expression downregulation of fatty acid oxidation in the peri infarction region. Downregulation of PPAR α mRNA displays that PPAR α may be a very important factor that regulates cardiac fatty acid oxidation in rats subsequent to myocardial infarction.