Bulk nanocrystalline Fe 56 Co 7 Ni 7 Zr 10 B 20 magnetic alloys of 10mm in diameter and 3mm in thickness were prepared by the spark plasma sintering method. The microstructure, thermal behavior and magnetic properties of the specimens were investigated by X-ray diffraction, differential scanning calorimetry, magnetic force microscopy, transmission electron microscopy and vibrating sample magnetometer. It is found that dense sintered materials with optimal magnetic properties could be obtained at the appropriate sintering temperature. Namely, as sintering temperature is 1150K, the saturation magnetization and relative density of sintered materials are up to 1.45T and 93.3%, respectively. An average grain size of ∼40nm of α-Fe crystallites has been obtained in the specimen sintered at 1150K.