In the development of the advanced spent fuel management process based on the molten salt technology, it is essential to choose the optimum material for the process equipment handling molten salt. As a part of assessment and application of the structural material for the molten salt handling system, corrosion behavior of 304, 304L and 316LN in the molten salts was investigated. Corrosion proceeded via three steps; the formation step of corrosion product in which rapid corrosion takes place until stable corrosion product is formed after the beginning of corrosion, the protection step against corrosion until breakaway occurs after the formation step of stable corrosion product and the advancing step of corrosion after the breakaway. In a molten salt of LiCl-8%Li₂O, the final oxide scales of Li₂Ni₈O₁₀ were formed, and also Li₂Ni₈O₁₀ in the molten salt of LiCl-8%Li₂O-1%Li₃N.