Auxetic cellular solids in the forms of honeycombs and foams have great potential in a diverse range of applications, including as core material in curved sandwich panel composite components, radome applications, directional pass band filters, adaptive and deployable structures, filters and sieves, seat cushion material, energy absorption components, viscoelastic damping materials and fastening devices etc.In this paper, the characteristic of wave propagation in sandwich panel with auxetic core is analyzed. A three-layer sandwich panel is considered which is discretized in the thickness direction by using semi-analytical finite element method. Wave propagation equations are obtained through some algebraic manipulation and applying standard finite element assembling procedures. The mechanical properties of auxetic core can be described by the geometric parameters of the unit cell and mechanical properties of the virgin core material. The characteristics of wave propagation in sandwich panel with conventional hexagonal honeycomb core and re-entrant auxetic core are discussed, and effects of panel thickness, geometric properties of unit cell on dispersive curves are also discussed. Variations of Poisson’s ratio and core density with inclined angle are presented.