Structural dispersion and materials dispersion properties of acoustic emission wave on carbon fiber reinforced plastics (CFRP) cross ply plate (0/90°) was evaluated as a function of distances, the fiber orientations and the directions of AE wave propagation using a pencil lead breaking simulate source and resonant type of AE sensor. In case of the structural dispersion, when a main detected frequency range was under 50 kHz, the quasi-longitudinal wave (QL) could be approximated to a longitudinal wave of one dimension. While, the quasi-transverse wave (QT) indicated strong structural dispersion that were shown phase transition of peak amplitude of the wave packet as a function of propagation distance. As regards materials despersion, velocity of wave front in the QL depended on both a wave propagated in the fiber bundles and a through pass of the wave. In the case of attenuation properties, the QL was observed strong variety with the detected frequency range and the direction of wave propagation. While, that of the QT was observed variably. In the case of power spectrum of wave packet, as peak frequency of these waves indicated different with the resonant frequency of the sensor, we have to consider the dispersion properties of composite plate in addition the response properties of AE sensor.