Ferritic Fe-Cr-Al based alloys have been considered as one of the most promising candidates as clad material for the accident tolerant fuel (ATF) owing to their excellent high temperature oxidation and corrosion resistance. The corrosion performance of Fe-Cr-Al alloys in highly oxidizing environments (such as high temperature, high pressure hydrothermal conditions) was very important to determine their suitability served as ATF cladding materials, especially for the domestic Fe-Cr-Al alloys. Herein, the corrosion behavior of domestic ferritic Fe-13Cr-4Al-2Mo-0.65Nb-0.4Ta-0.05Y alloy (mass fraction, %, designated as M2 hereafter) was examined via an autoclave at 360 ℃ in the condition of saturated vapor pressure with different dissolved-oxygen contents: namelytotal deoxidization (DEO), dissolved-oxygen concentration of 100 μg/L O₂ (DO100) and saturated dissolved-oxygen exposures (SDO) respectively for a long term. Then the formed oxide scales on M2 alloy were characterized by using XRD and SEM combined with EDS, and TEM in terms of their morphology and phase constituents, as well as elemental distribution and microstructure. The results indicated that the thickness of oxide scales on FeCrAl based alloy was 1.4, 2.3 and 0.1 μm in conditions DEO, DO100 and SDO, respectively. And with the increasing of dissolved oxygen contents, the phase constituent of the formed oxide scale changes from a mixed structure of spinel-like ((Fe, Cr)₃O₄), M₃O₄ and M₂O₃ in DEO conditions to the mixture of hematite-like (Fe, Cr)₃O₄ and (Fe, Cr)₂O₃ in DO100 conditions, and then a thin and dense monolayer structure of hematite (Fe, Cr)₂O₃ in SDO conditions. Correspondingly, the corrosion kinetics also changed from mass loss into mass gain. All the above results indicated that dissolved-oxygen had a significant influence on the corrosion of domestic FeCrAl based alloy in high temperature water, and it is worth noted that the domestic FeCrAl based alloy revealed an excellent corrosion resistance especially in SDO condition.