Shell-sand mixed seabed have been observed to reduce pore water pressure amplitudes within the seabed. This characteristic is advantageous for maintaining the stability of foundations supporting marine structures. However, previous research has predominantly focused on idealized conditions, such as wave-induced responses in homogeneous seabed, overlooking the natural heterogeneity of real seabed. This heterogeneity arises from marine biological activities and sedimentation processes, ensuring that natural seabed is inherently spatially heterogeneous. In this study, a series of experiments were conducted using physical models in a wave flume, testing under numerous wave conditions and seabed parameters. The objective was to analyze how varying proportions of shell mixtures affect wave-induced responses in seabed. Key aspects investigated included changes in pore pressure amplitudes. The findings offer valuable insights into how shell content influences the dynamic behavior of seabed under wave action.