An analytical solution is derived for the thermal buckling of a rectangular composite sandwich plate with angle-ply symmetric laminate
faces and a honeycomb core. The results show that the buckling mode that
sandwich plate will buckle into is dependent on the fiber orientation in the faces and the aspect ratio of the plate. For the square sandwich plate with angle-ply laminated faces, the highest critical buckling temperature is obtained with fibers orientated at 450. For the rectangular [(±θ)2/core]s sandwich plate with aspect ratio greater than 2, orientating the fibers in the faces to an angle around 630 will give the highest critical buckling temperature.