Objectives: To evaluate the degree of coronary artery stenosis with duration of myocardial early systolic lengthening derived from 2D speckle tracking imaging (2D-STD in patients with coronary artery disease (CAD). Methods: 185 patients with suspected CAD underwent 2D-STI before coronary CT angiography (CCTA) were included in this study. Duration of myocardial early systolic lengthening, LS, RS, and CS were measured by 2D-STI. According to the results of CCTA, the myocardial segment were divided into normal group (without coronary artery stenosis), mild stenosis group(coronary artery stenosis<50%), moderate stenosis group (50%>coronary artery stenosis < 70%) and severe stenosis group (70%>coronary artery stenosis <100%). Results: Duration of myocardial early systolic lengthening, LS, RS and CS were similar between mild stenosis group and normal group (P>0.05). Duration of myocardial early systolic lengthening was increased, and LS was decreased in moderate stenosis group than in normal group (P<0.05). Duration of myocardial early systolic lengthening was increased, LS, RS and CS were significantly decreased in severe stenosis group than in normal group (P<0.01). The cutoff value of early systolic lengthening for diagnose severe stenosis was 60.0 ms (area under ROC curve [AUCl=0.91, P<0.01), with the sensitivity 85.5% and specificity 74.1%, respectively. Conclusions: Duration of myocardial early systolic lengthening is prolonged in patients with significant CAD (moderate and severe stenosis), and might be used a useful parameter to identify patients with significant CAD (moderate and severe stenosis).