Abstract: Local structural changes during the crystallization process of the amorphous Fe₈₁P₁₂C₃Si_2.5Cu₁Mo_0.5 have been investigated by means of Mössbauer spectroscopy at room temperature. It is found that the whole crystallization process consists of two stages. The first stage (annealing between 300-360℃) is the nuclearation and growth of α-Fe phase;the second stage (above 360℃) is the nuclearation and growth of Fe₃P phase. And this alloy shows the optimal soft magnetic properties after annealing at 360℃. Correlations between the soft magnetic properties and structural changes are also discussed.