The present work focused on the buckling of four–layer symmetric laminate subjected to biaxial compression. Governing equations are derived based on Classical Laminated Plate Theory (CLPT). The composite plates are bonded by an internal elastic medium and surrounded by external elastic foundation. The influences of carbon fiber orientation angle and aspect ratio on critical buckling load are demonstrated for symmetric laminate. We analyzed four lamination scheme which fiber angle orientation is equal to 0°, 30°, 45° and 90°.
