The bubbling characteristics, the bubble rising velocity, the bubble diameter and the bed expansion ratio, were examined under vertical vibration with a two-dimensional fluidized bed. A high-speed camera was used to measure the bubble rising velocity and the bubble diameter. The bubble diameter and the bubble rising velocity had a minimum when a certain vibration strength was added to the bed. At such vibration strength, the bed expansion ratio was the largest. When the convective particle flow enhanced by vibration appeared, the particle flow was significant to clarify the bubbling characteristics under a vibration condition.