Abstract: Nanocrystalline TiB2/Fe3Al composite powders have been synthesized by mechanical alloying and subsequent heat-treatment of Fe-Al-Ti-B quaternary elemental powders.The microstructure and properties of the nanocrystalline powders were examined by X-ray diffractometer (XRD),differential scanning calorimetry(DSC),scanning electron microscopy(SEM),transmission electron microscopy(TEM) etc.The supersaturation solid solution of Fe(Al,Ti,B) was firstly formed and then transformed into an amorphous state during the milling process.The order degree and grain size were continuously decreased.After milling for 40 h,the crystalline size of the Fe(Al,Ti,B) solid solution was 9.6 nm.The composite powders were decomposited into Fe3Al and TiB2 nanocrystalline during subsequent heat-treatment.The grain size and structural order degree of Fe3Al and TiB2 increased during heat-treatment.