Abstract: The characteristic equations for leaky Lamb waves in fluid-saturated porous plates with loading liquid are derived in this paper by using the Biot's theory.A mathematical algorithm is developed for estimating the propagation velocity of leaky Lamb waves in a plate of cemented glass beads with open and sealed boundaries.The effect of surface flow impedance of the porous plate on propagation velocity and amplitude attenuation of the two lowest modes is evaluated.By using a broad-band ultrasonic transmission spectrups measuremellt technique,the dispersion relations of leaky Lamb waves at certain frequency region are measured.The predicted and experimental results are found to be in good agreement.