Abstarct: Carbon nanotubes have unique physical and mechanical properties that make them to be used as one of the ideal fillers to reinforce polymeric materials. Adding a very small amount of carbon nanotubes to the polymers improves their mechanical properties significantly. However, in order to use all advantages of the unique properties of carbon nanotubes, there are still many subjects that need to be investigated. To this end, in this research, the effect of adding 0.25, 0.5 and 1 weight percentages of carbon nanotubes to the epoxy resin of glass/epoxy composite on the critical buckling load, stored energy and the specific stored energy of the composite plates under compressive loading is studied. Scanning electron microscopy images were obtained from cross-sections of specimens to investigate the scattering quality of different percentages of nanotubes in composites. Also, the values of Young’s modulus of glass / epoxy and carbon / epoxy composites were obtained by simple tensile testing and these values were used to validate the experimental buckling tests results using finite element software. Results show that adding 0.5 weight percent of carbon nanotubes into the epoxy resin has the most effect on the critical buckling load of glass/epoxy composite plate and increases this load more than 2.5 times with respect to the specimen without carbon nanotube. Moreover, replacing T400 glass fibers with T300 carbon fibers in glass/epoxy composite plate, leads to the increase of buckling load by 211.9 percent. Comparison between analytical and experimental results indicates that analytical results are in good agreement with those obtained from the experimental tests.