The phase formation and crystallization kinetics during the thermal treatment of amorphous Zr 60Al 15Ni 25 alloy were investigated by differential scanning calorimetry (DSC) and X-ray diffraction (XRD). By lowering the isothermal annealing temperatures, it is revealed that the crystallization of the amorphous Zr 60Al 15Ni 25 alloy consists of a primary transformation followed by a polymorphic transformation, corresponding to the precipitations of hexagonal Zr 6Al 2Ni and the Zr 5AlNi 4 with a U 3Si 2-typed superstructure. The primary phase being Zr 6Al 2Ni rather than Zr 5AlNi 4 in the crystallization is because the latter has a complex structure and its formation requires the diffusion of Al and Zr atoms on a large scale.