Thin sheets stiffened with lattice structures are used widely in many engineering industries. Investigation of stability behavior for the grid structures and determination of the buckling load under compressive loads is an issue that has attracted the attention of many researchers; and extensive studies have been done in this field. In this paper, a new grid called Diacube is introduced and its buckling load is examined. For this aim, first, the buckling behavior of 5 common types of stiffened flat lattice panels containing hexagonal, triangular, square, diamond and kagome grid are investigated under compressive axial load; and the results are compared with Diacube grid. The effect of network density used in each structure on the buckling of these structures will be studied under different boundary conditions. In addition to common grids,. Regarding to the mass difference of samples, specific critical load parameter (the buckling load to mass ratio) is used for comparison between the structures. Using the finite element modeling and numerical analysis, the grid that has the highest buckling load in each boundary condition is determined It is found that if unloaded edges in lattice panels are simply supported, this new Diacube grid will have the highest buckling load among all structures. Finally, validity of the numerical result obtained for two samples of the structures including hexagonal and Diacube grid is evaluated experimentally; and the numerical results are confirmed.