Abstract: Objective: Myocardial remodeling and time course and magnitude of infact involution after acute myocardial infarction undergoing selective percutaneous coronary intervention(PCI) opterations are not completely knowed in humans. This subject is to explore the changes and correlations of relative amount of hyperenhancement, global left ventricular function and regional wall thickening by using 3T cardiac magnetic resonance. Method: To collect patients with acute myocardial infarction in our hospital from August 2014 to March 2016. They were examination by MRI before PCI operation and reexamine at one week and half year after PCI operation. To observe and compare the changes of relative amount of hyperenhancement, global left ventricular function and regional wall thickening in three groups. Result: Comparison of relative amount of hyperenhancement: relative amount of hyperenhancement was reduced by about 30% during the first week after operation, which were respectively(13.1 ±7.6)%,(9.4 ±6.6)%,(8.9 ±6.4)% at the time before PCI operation, one week after PCI operation and half year after operation, the difference was statistically significant(P<0.05). Comparison of global left ventricular function: the global left ventricular function increase gradually by time. LVEF were respectively(43.9 ±10.9)%,(46.7 ±10.8)%,(52.3 ±12.5)% at the time before PCI operation, one week after PCI operation and half year after operation. LVEDV were respectively(161.4 ±54.0)mL,(1.686 ±53.0)mL,(168.5 ±52.6)mL. LVSDV were respectively(91.62 ±43.5)mL,(91.3 ±43.7)mL,(82.5 ±43.4) mL. he difference was statistically significant(P<0.05). The changes of regional wall thickening: Regional wall thickening was increased by remote segments,adjacent segment and which transmural extent of hyperenhancement is 1%~25%, 26%~50%, 51%~75% and no significant change by which transmural extent of hyperenhancement is 75%~100%.Regional wall thickening decreased progressively with increasing transmural extent of hyperenhancement(P<0.05). Conclusion: The efficacy of PCI operation may reduce the relative amount of hyperenhancement, improve regional left ventricular function and regional wall thickening. 3T magnetic resonance can accurately evaluate the efficacy of PCI in patients with coronary heart disease.