The effect of ladle degassing of aluminum-deoxidized steels with carbon concentration from 0,09 to 0,33% on the oxygen content in the metal has been studied. It has been established that in this case metal oxidation and oxidation potential of the “metal-slag” system are controlled by the depth of deposition deoxidation. Change of metal oxidation during vacuum treatment is determined by changes of aluminum concentration, metal temperature, and Al2O3 activity and may have a different sign. The pattern of change in the concentration of bound oxygen in steel as a result of vacuum treatment is opposite to the pattern of change in the metal oxidation. The change in the content of total oxygen in the metal during degassing depends significantly on the concentration of carbon in the steel.