Rest gated blood pool scan (Rest GBP scan) and dipyridamole $^{99m}Tc-MIBI$ SPECT were Performed in 34 patients with or suspected coronary artery disease. Both studies were performed within $2sim32$ days (mean 8.1 days). A significant correlation was present between left ventricular ejection fraction (r= -0.7356, p<0.001) and peak ejection rate and peak filling rate in rest GBP scan and perfusion defect in MIBI SPECT. And there were acceptable correlations (0.05<p<0.001) between regional ejection fractions and perfusion defects corresponding to the regions. There were 39 segments of fixed (rest) perfusion defects in MIBI SPECT and there was a significant difference in perfusion defect according to the regional wall motion (normal or mild hypokinesia in 23 regions: $26.2{pm}10.8%$, severe hypokinesia, akinesia or dyskinesia in 16 regions: $78.2{pm}23.7$, p<0.001). These data indicate there is a significant coupling between the degree of myocardial perfusion and the myocardial functional change in coronary artery disease.