Background: In acute myocardial infarction(AMI), both of coronary flow patterns and angiographic TIMI myocardial perfusion(TMP) grade, measured after primary stenting, have been known as prognostic factors and are related with the degree of microvascular integrity. However, the correlation between coronary flow patterns and TMP grade has not been elucidated. Subjects and Methods: Forty-nine patients with AMI(53짹14, 39 males), who showed TIMI 3 flow after primary stenting(with GuardWire protection 28, without protection 21) were studied. Coronary angiographic TMP grade were evaluated. Averaged peak velocity(APV) and diastolic deceleration time(DDT) were measured after stenting with a Doppler wire at baseline(b) and intracoronary adenosine(24-48µg) induced hyperemia(h). Coronary flow reserve(CFR), and microvascular resistance index(MVRI) were calculated. Results: In AMI patients with TIMI 3 flow after primary stenting, TMP grade 0/1 was 18.4%, TMP grade 2 was 26.5% and TMP 3 grade was 55.1%. APV significantly increased, MVRI significantly decreased, and DDT significantly increased as TMP grade increased(table). There was significant correlation between TMP grade and MVRI(baseline; r=-0.465, p<0.001, hyperemia; r=-0.548. p=0.001) and between TMP grade and DDT(baseline; r=0.387, p=0.006, hyperemia; r=0.388. p=0.006). There was no correlation between CFR and TMP grade. Conclusion: In AMI patients with TIMI 3 flow after primary stenting, coronary angiographic TMP grade showed significant correlation with coronary flow patterns which represent the degree of microvascular integrity.