Background: While recent advances in percutaneous coronary interventions with drug-eluting stents, treatment of coronary bifurcation lesions represents a challenging area in interventional cardiology. Restenosis at the ostium of the side branch (SB) remains a problem. Vascular stenosis due to atherosclerosis might be affected by hemodynamic factors, such as flow separation and oscillatory shear stress. The purpose of this study is investigating the flow characteristics and distributions of the hemodynamic wall parameters (HWP) in the coronary bifurcation between left anterior descending artery and first diagonal branch according as different angle. Methods: HWP, such as time averaged wall shear stress (TAWSS), oscillating shear index (OSI), and wall shear stress (WSS) distributions in coronary bifurcation model were calculated under different bifurcation angle condition (30, 45, 60, and 90^o). Coronary bifurcation models were made from geometric data of computed tomogram (CT). Atheroma volume was analyzed with CT according as bifurcation angle (BA) in patients with stable angina. Results: The bigger the BA, the lower TAWSS and the higher OSI at SB [TAWSS(Pa): 0.133, 0.020, 0.045, 0.060, OSI: 0.309, 0.472, 0.442, 0.469 at 30, 45, 60, and 90^o, respectively](figure). The low shear zone was widening when the BA increasing. The mean volume of side branch in small BA (n= 12, <45^o) was significantly smaller than large BA (n=15, >45^o) (12.5짹6.2 mm³ vs. 25.6짹10.7 mm³), p = 0.035). Conclusion: Over 45 degree of BA might be more atherogenic and have restenosis risk of SB after main branch intervention. We suggest that small BA might be more likely treated with just one stent in main vessel when there is no flow limitation.