Based on Laminate plate theory, a formulation, including the effects of shear deformation and rotary inertia on the characterization of plate wave propagation, was derived. The characteristics of plate waves propagating were investigated and the influences of frequency, plate thickness and propagating direction were clearly known. A health monitoring system was built and the plate waves generated by lead break source were received by acoustic emission (AE) sensors. By the wavelet transform , the time-frequency domain of AE signal was derived. For a certain frequency, the first peak of the magnitude of wavelet transform indicates the arrival times of plate waves. The locations of lead break source and the delaminations of plate were compared with the predictions of theory.