This paper shows vibration behavior of a circular cylinder subjected to jet-flow from a narrow gap in the vicinity of wall by using computational fluid dynamics (CFD) simulation. We investigated the effects of the distance between the centerline of jet-flow and the cylinder center. And these CFD simulation results are comparred with the experiments in published paper. As a result, the vortex shedding vibration phenomena and the fluid elastic vibration phenomena can be confirmed in a circular cylinder subjected to jet-flow from a narrow gap as well as in the case of the experiment.