Abstract: In order to clarify the influence of Taylor patch onthe flow field in a new (S-type) arterial end-to-side anastomosis, anumerical investigation was carried out in terms of the flow patterns, wallshear stresses, and wall shear stresses gradients. The numerical resultsshowed that the Taylor patch had an great effect on the flow field at thedistal anastomosis. At the distal anastomosis, more smooth distributions offlow patterns were obtained, and the second flow and the wall shear stressgradients decreased almost 34.48% and 52.22%, respectively, to improvethe haemodynamics, while at the artery bottom the wall shear stress wasreduced about 30.33% to promote atherosclerosis. Therefore, it can not beconcluded that the Taylor patch has superior treatment in S-type bypassgraft by only considering haemodynamic factors. Moreover, a lot of animaland clinical experiments are needed to be carried out with numerical study.