The oxidation behavior of the amorphous ribbons heat treated under different temperature and holding time was deeply investigated. The oxidation morphology was observed by using of SEM equipment. The experiment results show that at the initial stage of oxidation, the morphology of the oxides is small round particles. With the holding time increasing, the small round oxides began to gather into a larger oxide. What's more, the amount of the oxides increased. Besides, the experiment results also proved that the existence of the impurity and defects accelerate the oxidation and the morphology is also round particles. Increasing the heat treatment temperature, part of the oxidation morphology changed, some cracks formed in the oxides. Altogether, the occurrence of the oxidization made the magnetic properties of the amorphous ribbons deteriorate.