Two large exothermic reaction peaks at 658 and 690 K are observed in the differential scanning calorimetric (DSC) curve for the amorphous metallic alloy, Ni65Cr16P19. Extensive DSC and X-ray diffractometer measurements were carried out for pre-annealed samples, and it is concluded that the two peaks are due to crystallization of Ni and stable Ni3P phases, respectively. The expanded lattice constants of these phases can be explained by assuming that a small amount of Cr atoms were dissolved in these crystalline phases. As for the metastable Ni3P ponfirmation of its presence by X-ray measurement could not be obtained. These results may be interpreted by considering that the metastable phase appears only in the thin film region of the sample.