An analytical method was presented to determine the delamination buckling load and the growth of one-dimensional delaminated beam-plates. In this study, the symmetry in delamination with respect to the center of the beam-plate was not assumed. The delamination was arbitrarily located in the longitudinal and thickness directions. The effects of the delamination length, and location on the buckling load and the growth were investigated with consideration of the transverse shear deformation. Results of the analysis showed that the delamination buckling load was dependent on the configuration of the delamination. For the relatively thick delamination, the buckling load of a center located delamination was higher than that of an off-center delamination. The shear deformation effect lowered the buckling loads and increased the energy-release rates. The expreiments on delaminated graphite/epoxy unidirectional specimens were also performed to determine the buckling load and to observe the growth characteristics. Results of the experiments showed good agreement with analytic results and there existed various postbuckling characteristics depending on the configuration of delamination.