Abstract: The microstructure of 0Cr25Al5 stainless steel as quenched at 500℃ was studied by X-ray diffraction,scanning electron microscope and transmission electron microscope. The results show that the hot-rolled 0Cr25Al5 stainless steel has a dual-phase structure composed with α and α’ phase. Yet, there is no obvious precipitate in the SEM analysis. However,0Cr25Al5 stainless steel after 500℃ still has a dual-phase microstructure. The chromium-rich α’ phase in lamellar shape is distributed along the grain boundary of the substrate α phase, the α’ phase is present with ＜110＞ preferred orientation and ordered along 110 plane with Fe atom and Cr atom. The α and α’ phase have a coherent structure along the phase boundary.Yet, the difference in lattice constants between the two phases is larger and have a large lattice distortion energy.