Hemodynamics is widely believed to correlate with the stenosis of coronary artery bypass graft (CABG). Although some researchers had investigated distal anastomosis, further studies upon the proximal anastomosis are still necessary as the initiation and growth of the stenosis process may be influenced by the nature of the flow at the proximal anastomosis. Therefore in this project, flow characteristics of proximal anastomosis models were studied numerically in order to enhance the understanding of the stenosis pathophysiological process and particle image velocimetry (PIV) measurements were also carried out to validate the numerical simulation results. Two models (viz. 90deg and 135deg anastomotic models) were firstly designed to mimic the proximal anastomosis of CABG for left and right coronary arteries respectively. A fair match between numerical and experimental data was observed in terms of flow characteristics, velocity profiles and WSS distributions under physiological flow conditions. The overall difference between their velocity profiles ranged from 8% to 54%. It is evident from the findings that PFV measurement can obtain quantitative results as accurate as LDA and numerical simulation is able to provide much detailed information with enough mesh density. In addition, the 135deg model would result in better patency rate based on hemodynamic analysis.