An oscillatory motion of nonmagnetic object in magnetic fluid under the oscillating magnetic field was treated experimentally. Oscillating magnetic pressure is induced in a container of magnetic fluid with the oscillating magnetic field. This oscillating magnetic pressure causes the oscillatory motion of nonmagnetic object which is introduced into magnetic fluid. This oscillating system with a plexiglass column and a glass sphere as nonmagnetic object shows the similar characteristics to it of motion of the magnetic fluid itself under the oscillating magnetic field. The effects of some quantities such as the length and weight of column and the position of the object center against the center of the applied magnetic field on the oscillation have been clarified.