Objective To explore the value of coronary flow reserve(CFR) evaluating myocardial ischemia measured by adenosine triphosphate (ATP) stress transthoracic Doppler echocardiography (TTDE),and the feasibility of CFR to predict coronary stenosis.Methods Fifty-four patients suffering chest pain with known or suspected coronary artery disease were performed ATP stress TTDE to measure resting and maximum expansion coronary blood flow velocity and calculate CFR.all patients were performed by coronary angiography (CAG) and single-photon emission computed tomography (SPECT) myocardial perfusion imaging.Results ① To evaluate myocardial ischemia,there was not statistical significant difference between non-invasive CFR and SPECT myocardial perfusion imaging(P ＞0.05).CFR≤2.0 was the best cutoff value for evaluating myocardial ischemia which yielded a sensitivity of 93.3 ％ and specificity of 89.7％.②Coronary artery stenosis was negatively correlated with CFR (P ＜0.001).ROC curve analysis demonstrated that CFR≤ 1.60 yielded a sensitivity of 92.3％ and specificity of 73.3％ to predict coronary stenosis significantly.Conclusions CFR measured by ATP stress TTDE can evaluate myocardial ischemia of coronary artery disease and predict LAD significant stenosis before CAG.Using CFR and CAG has important clinical value for choosing treatment of stable coronary artery disease.