The corrosion behavior among five austenitic alloys (304, 310S, 600, 800H, and 904L) was investigated in supercritical carbon dioxide (SC-CO2) environment at 650 °C and 20 MPa for 500 h. Weight gain method was used to evaluate the corrosion resistance among these materials. The morphology, structure and composition of the oxide films formed on the surface of materials were investigated by using micro-analytical methods. The results show that the weight gain at 500 h is decreasing with the order of 304, 800H, 600, 310S and 904L. 304 has the worst corrosion resistance, while 904L has the best corrosion resistance. The oxide formed on all iron-based austenitic alloys (304, 310S, 800H and 904L) has a multilayer structure. The outermost layer is Fe3O4, and the inner layers are rich in Cr. The surface oxides formed on the Nickel-based austenitic alloy (600) are rich in Ni, Cr elements, which show the presence of NiO and NiCr2O4. In this environment, the major elements (Fe and Ni) in the austenitic alloys will significantly affect the corrosion process, which in turn changes the composition and structure of the surface corrosion products, and ultimately determines the corrosion resistance among materials.