Background: Fractional flow reserve (FFR) represents functional status of coronary stenosis. However, sometimes there are the dissociative coronary lesions between functional significance and angiographic stenosis. Methods: 326 patients (399 lesions) who underwent pre-interventional FFR measurement were enrolled. Functional significant coronary artery was defined as FFR<0.80. Anatomical significant coronary lesion was defined as % diameter stenosis (DS) ���50%. All patients were divided into 4 groups as: true negative (TN) group FFR���0.80 and DS<50%, false negative (FN) group FFR<0.80 and DS<50%, true positive (TP) FFR<0.80 and DS���50%, and false positive (FP) group FFR���0.80 and DS���50%. The clinical risk factors and lesion characteristics were compared FN with TN, and FP with TP groups (Fig.1). Results: Function and anatomy dissociation were observed in 44% (178/399).The clinical risk factors were not different between groups. In TP and FP groups, multivariate analysis revealed lesion length, male gender and left anterior descending(LAD) artery lesion were independent predictors for functional significance (LAD lesion, OR 2.64, 95% CI 1.49-4.66, p=0.001; Lesion length, 1.03, 1.01-1.05, 0.006; male gender, 1.97, 1.09-3.54, 0.025). In TN and FN groups, multivariate analysis revealed reference vessel diameter (RVD) was an independent predictor for functional significance (0.23, 0.07-0.69, 0.009). Conclusions Function and anatomy dissociation was not rare in coronary artery disease. Therefore, careful attention about the location of lesion, lesion length, gender, and RVD should be paid before making a procedural decision.