Mechanical milling was performed on the alloy Cr72Fe 28. X-ray diffraction and Mossbauer spectroscopy were used to follow the progress of the structural variation. The experimental results can be interpreted by assuming that the milled powders are composed of a small amount of crystalline component and two disordered components: one with a random densely packed structure and the other with a random loosely packed structure. Moreover, differential scanning calorimetry was used to obtain the crystallization temperature. A mechanism was proposed to describe the formation of the disordered structures as well as the structural stability in this alloy.