The present study tested Type 316L stainless steel (SS316L) with and without a preformed boride layer in a molten chloride salt at 800°C for 100 h. The results showed that the preformed boride layer on the specimen surface is stable and can completely inhibit the depletion of Cr of the steel. No attack layer by the molten salt was detected for the specimen with the preformed boride layer. Therefore, the data from the present study indicate that a preformed boride layer can be a protective layer to mitigate the corrosion of SS316L by molten salts.