High temperature oxidation of Fe-13%Cr and Fe-17%Cr stainless steels at the temperatures between 1200℃ and 1300℃ in dry oxygen environment has been studied. The oxidation rate was more influenced by the partial pressure of oxygen than the temperature. The oxidation was proceeded by forming nodular oxides at the scale/metal interface. The decrease in oxidation rate with increasing temperature was due to the prevention of nodular oxide growth at the scale/metal interface by lowering oxygen potential which was caused by the evaporation of CrO₃(g). The scale breakaway of the Cr₂O₃ layer formed at the scale/metal interface was restrained by the formation of internal oxides constituting mainly of SiO₂