Honeycomb Composite Sandwich Structure (HCSS), is one of the novel materials that has been adopted universally to form major structural components of aerospace, marine and automotive vehicles due to its high strength to weight ratio and high energy-absorption capabilities. In this research paper, the scope to study the general characteristics of guided wave (GW) propagation in an HCSS plate with the presence of a high-density (HD) core subjected to timedependent transient surface excitations is presented numerically and experimentally. Significant effects are detected due to the presence of HD core in terms of decay in amplitude and reduction in group velocity of the output GW signals. A two-dimensional (2D) numerical model is made in ABAQUS. An effective non-reflecting boundary condition (NRBC) is modeled in ABAQUS in order to mitigate the undesirable boundary reflections during numerical simulation. Good agreements between the numerical and experimental results are noticed for all the cases studied.