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 316LN ss weld in the molten salts was investigated. In a molten salt of LiCL-Li₂O, the oxide scales of LiCrO₂ and Li₄MoO₅ were formed at the rate of simular linear kinetics. But in the molten salt of LiCl-Li₂O-Li₃N, the oxide and nitride scales of Li₄MoO₅, CrN and Mo₂N were formed at the rate of simliar linear kinetics. The corrosion rate of 316LN ss in the molten salt of LiCl-Li₂O was lower than that in the molten salt of LiCl-Li₂O-Li₃N.