We investigated the influence of stent implanted in left main coronary artery trifurcation on blood flow by means of CFD. We simulated various stent positions and arrangement patterns considering KBT. The velocity and WSS (wall shear stress) distribution were found to depend on the stent arrangements. In addition, a strut position inhibiting the inflow velocity peaks into the branched (LCX) vessel exhibited a strong impact, which provided suppression of WSS on the high-lateralside surface of the LCX entrance. By KBT, such an impact of stent implantation can be avoided.