Background: Foreshortening of a vessel segment may be imperceptible during traditional angiography. This limits visual coronary analysis as well as 2D quantitative coronary angiography systems (QCA).Rotational angiography provides a dynamic multiple-angle perspective of the coronary tree during a single contrast injection. The 3D model of a vessel segment of interest can predict the appropriate gantry angle for subsequent interventional guidance. Objectives: The goal of the study was analyze the accuracy of this new 3D QCA system. Methods: 3D QCA, 2D QCA, and IVUS QCA were performed in 12 patients (15 vessels with 27 segments). The obtained values of branch to branch length and vessel diameter were analyzed by T test and pearson correlation analysis. Results: The branch to branch length measured by 3D QCA was more correlated with that of IVUS results (mean 짹 SE, SD: 0.77 짹 0.26, 1.34) than that of 2D QCA (mean 짹 SE, SD: -1.42 짹 0.51, 2.7). Vessel length measured by 3D QCA was more correlated with IVUS than 2D QCA(Pearson correlation : 3D QCA and IVUS:0.966, 2D QCA and IVUS: 0.962). Vessel diameter measured by 3D QCA were more correlated with IVUS than 2D QCA(Pearson correlation : 3D QCA and IVUS:0.836, 2D QCA and IVUS: 0.588). Conclusions: 3-D QCA permits an accurate, reproducible and sensitive comprehensive three-dimensional geometric analysis of the coronaries and is superior to 2-D QCA with respect to extended length and diameter evaluation.