Inclusions have a great infuence on the quality of FeSiB amorphous ribbon. The evolution behavior of inclusions was analyzed. The results show that the spherical and elliptical inclusions, consisting of Al₂O₃ and SiO₂, mainly come from industrial pure iron. Ellipsoidal inclusions of 20–30 μm in pure iron were removed by foatation during the smelting process, and spherical inclusions of 1–3 μm combined with deoxidized products in FeSiB melt form Al₂O₃·SiO₂ and CaO·Al₂O₃·SiO₂ inclusions. Some inclusions accumulated on the inner wall of the nozzle during the spraying process, and others fowed out of the nozzle and remained in FeSiB amorphous ribbon. By controlling the total oxygen content in industrial pure iron to 31 × 10?6, clogging on the inner wall of the nozzle can be reduced and the free surface smoothness of the amorphous ribbon can be improved.