In the current study, the amorphization behavior of mechanically alloyed Ni57Zr20Ti22Ge1 powder was examined in details. The conventional X-ray diffraction results confirm that the fully amorphous powders formed after 5 hours of milling. The thermal stability of the Ni57Zr20Ti22Ge1 amorphous powders was investigated by differential scanning calorimeter (DSC). As the results demonstrated, the glass transition temperature (Tg) and the crystallization temperature (Tx) are 761 K and 839 K, respectively. The supercooled liquid region ΔT is 78 K. The appearance of wide supercooled liquid region may be mainly due to the Ge additions which cause the increasing differences in atomic size of mechanically alloyed Ni57Zr20Ti22Ge1 powders.