A three-dimensional direct numerical simulation is carried out to predict the surface oscillation and flow structure of isothermal liquid bridges of 5 cSt silicone oil held vertically between solid disks.By subjecting liquid bridges to various horizontal vibrations,the surface resonance frequencies are clearly determined numerically and compared well with the existing analytical model predictions.The investigation on the flow structure inside the liquid bridge reveals,for the first time,the flow structure and the existence of transversal vortices inside the liquid bridge when a horizontal vibration is applied.