Abstract：Nonlinear vibrations of a simply supported rectangular plate subjected to transverse exitation are experimentally investigated in this paper. The plate is placed in a special test frame in which four thick blocks with V-grooves hold the test plate to enforce required boundary conditions. The two groups of plate edges are movable during the test. A shaker fixed above the plate is used to provide the desired excitation. The resonance frequencies are obtained by hammering method and the vibration experiments are carried out in the resonance frequency zones. Nonlinear analyses are made by changing the exciting frequency and amplitude. The waveforms, phase portraits and amplitude spectrums are obtained to show that this system can exhibit complicated nonlinear dynamic characteristics, including periodic doubling bifurcations and chaotic motions under certain excitation frequency and amplitude conditions.