This chapter is focused on strength evaluation of honeycomb ‘ber-reinforced polymer (HFPR) sandwich panels with sinusoidal core geometry, in terms of both experimental investigation and theoretical analysis. The sandwich structures consist of core and facesheet components, where core materials are primarily subjected to out-of-plane compression and shear, and the facesheet carries mainly membrane forces. Therefore, the ‘rst objective is to study the core material under out-of-plane compression. Chopped strand mat (ChSM) is used for the core material, which is composed of E-glass ‘bers and polyester resin. The facesheet is made of several layers of ChSM, 0°/90° E-glass ‘ber, and polyester resin. The ChSM material is used at the interface between the core and facesheet as a bonding layer. These component parts are joined by the contact molding manufacturing process. As a result, the number of the ChSM bonding layers and core thickness plays an important role on the compressive strength of the panel. Analytical models are provided to predict the pure compressive and buckling strength, which are veri-‘ed through ‘nite element (FE) results. Compression tests are further carried out to correlate with the analytical results. The number of the ChSM bonding layers and panel core thickness de‘ne each specimen type. Different failure modes are obtained for different parameter combinations, and their linear and failure responses are described.