Laminated composite materials are used in most of engineering applications such as aerospace industries, marine applications, traortation civil engineering and so, because of their lightness, resistance against corrosion and very high strength to weight ratio. Design concepts of these plates that lead to the increase in the buckling load can directly lower the Structural cost and/or weight So it seems necessary to investigate mechanical behavior of these materials to gain an optimum design. In particular, the analyses of buckling problems are important due to their complicated mechanism in comparison with static problems. Therefore lots of researchers have studied the behavior of laminated plates and have presented different theories in this field. These theories can be divided into two groups. The first group is equivalent single layer theories which include developed in MATLAB environment . Local buckling load coefficient vs. different length to width ratios for different boundary conditions were represented as tables and graphs. Buckling load coefficients for different layers and orientations were adopted, too. Finally, it is shown that it's useful to employ zig-zag theory for laminated composite plates, specially thick laminated composite plates, since this theory shows the kinematic of the plate better than the othe r theories. Keywords : Laminated plates, local buckling, zig-zag theory, shear deformation theory, finite strip method
