Abstract The buckling load and post-buckling deformation of a composite beam-plate having two non-overlapping delaminated regions under axial compression is studied by using the generalized differential quadrature (GDQ) method. Applying the GDQ method to each region and using the continuity conditions in transverse displacements, the slopes, the moments and shear forces for upper and lower parts at tips of delamination, the problem will transform to the generalized eigen problem. Various combinations of delaminated length, depth and locations to obtain the buckling load and post-buckling deformation are investigated.