Abstract: The corrosion behavior of 310S and 316L austenite stainless steels in the supercritical carbon dioxide (S-CO₂) environment of 600 ℃/20 MPa was investigated. The general corrosion tests were carried out in an aoutoclave for 500 h. The morphology, composition and structure of the oxide films on sample surfaces were characterized by scanning electron micro-scopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The results show that the corrosion resistance of 310S stainless steel was higher than that of 316L stainless steel, and the weight gains of stainless steels 310S and 316L corroded for 500 h were 6.82 mg/dm² and 35.25 mg/dm², respectively. The thickness of oxide scale on 310S was about 1 μm, with an outer Fe-Cr-Ni spinel layer and an inner Cr₂O₃ layer which was dense and continuous. The thickness of oxide scale on 316L was about 5 μm with an outer Fe₃O₄ layer and an inner Fe-Cr-Ni spinel layer which was loose and not protective. The the difference in the corrosion behavior between 310S and 316L was due to their different Cr concentrations.