The laminated composite plates with fibres are subjected to uniaxial or biaxial compressive forces as well as shear forces or combination of shear, compression, and lateral loading. These forces may cause the buckling of the composite plate structures. Hence, structural instability becomes a major concern in safe and reliable designs of the composite plates. In order to get the practical limits of the load-carrying capacity of the composite laminated plates, the postbuckling behaviour is studied to establish sustainable additional loads after buckling. This book presents the postbuckling behaviour of laminated composite for square and skew plates with symmetric layup configurations subjected to In-plane uniaxial and shear loading using ABAQUS software for different variables like loading conditions, end conditions and different materials. The accuracy of results is verified by comparing the results available in the literature. Results are presented through a number of graphical plots.