Abstract: The effect of normal annealing process on the magnetic properties of amorphous Fe78Si9B13 alloy was investigated experimentally. It was found that when a moderate amount of crystalline α-Fe(Si) phase precipitates, the induced magnetic anisotropy forms, of which the easy magnetization direction is perpendicular to the alloy ribbon surface. A good constant permeability is provided for the alloy if annealed at 470°C for 120 min or 480°C for 60 min. According to the relation of residual induction ratio Br/B800 to annealing temperature/time, the influence of crystallization behavior in the alloy's surface layer and matrix on transversely induced magnetic anisotropy resulting from magnetoelastic coupling was also discussed.