To investigate the effect of quercetin on the expression of NOX2, eNOS, and iNOS genes and proteins in the rabbit heart after myocardial ischemia/reperfusion injury, a MI/RI model was established in New Zealand white rabbits by myocardial ischemia for 30 min and reperfusion for 12 h. This evidence concerns the gene NOS3 and myocardial ischemia.