Objective:By comparing with conventional coronary angiography(CAG),we sought to investigate the diagnostic value of dual－source CT coronary angiography(DSCTA)to diabetic patients with coronary artery stenosis. Methods:A DSCTA inspection was established to 81 cases of type 2 diabetes in patients with suspected coronary heart disease,along with a variety of scanned images reconstructed by the Workstation. We then assessed 12 segments of the proximal diameter ≥2.0 mm,selected patients of stenosis degree ≥50%,and adopted 2x2 contingency table with chi－square test. Results:A total of 68 cases showed stenosis ≥50% in all 81 patients,and 42 out of these 68 patients(61.8%)had multiple－vessel stenosis,and CAG examination was performed in all these 68 patients. Sixty－eight patients along with a total of 793 coronary artery segments were clear and evaluable,with the evaluable rate of 97.2%. CAG was set as the gold standard,and the predicted values of sensitivity,specificity,positive predictive value,negative with DSCTA detected vascular stenosis ≥50% were 95.6%,97.7%,89.7% and 99.1%,respectively. The difference between the two methods was not statistically significant(P > 0.05). The sensitivity(97.4% vs 93.2%),specificity(97.6% vs 97.9%),positive predictive value(89.4% vs 90.2%),and negative predictive value(99.5% vs 98.6%) of DSCTA detected coronary artery stenosis between rate < 70 beats/min and ≥70 beats/min in diabetic patients was not significantly different(P > 0.05). Conclusion:DSCTA has clear image,rapid scanning speed and is non－invasive,etc,which is not influenced by the heart rate. It is an effective coronary artery screening method,especially for type 2 diabetic patients with coronary heart disease.