This is a retrospective study aimed at the clinical application of 64-slice computed tomography angiography (CTA) in evaluation the lumen before and after coronary artery stent implantation. We collected the coronary artery imaging data of 46 patients undergoing 64-slice CT before coronary artery stent implantation from July 2006 through May 2007; we also collected the data of 21 patients with 34 coronary artery stents in the same period to determine the diagnostic accuracy of CTA before and after coronary artery stent implantation. The results showed that, in 46 patients, 64-slice CT enabled the visualization of the entire coronary tree with diagnostic image quality. Sensitivity, specificity, and accuracy for the detection of stenosis > or = 50% were 92.11%, 95.64% and 94.97%, respectively. In 21 patients with 34 stents implanted, 23 (67.65%) stents showed no stenosis, 8 (23.53%) stents showed low degree of restenosis, and 3 (8.83%) stents showed high degree of restenosis. In conclusion, we can accurately evaluate the degree of stenosis of lumen before and after coronary artery stent implantation with the application of 64-slice CTA.