The　effect　of　SiO2　nanoparticles　and　flow　rate　on　the　corrosion　behaviors　of　304　and　316　L　stainless　steels　in　quaternary　nitrate-nitrite　(QNN)　molten　salt　are　comparatively　investigated.　The　results　show　corrosion　of　304　and　316　L　specimens　in　QNN　with　nanoparticles　are　lower　than　that　in　QNN.　Compared　to　the　corrosion　weight　loss　(m(mass))　in　QNN　with　nanoparticles,　the　m(mass)　of　304　and　316　L　in　QNN　is　separately　increased　by　25.2%　and　60.4%　at　2　m/s　after　1000　h　due　to　the　sedimentation　of　the　nanoparticles.　Besides,　the　m(mass)　of　304　and　316　L　specimens　in　nanofluids　at　2　m/s　are　individually　16.8%　and　13.8%　higher　than　those　at　0.6　m/s.　The　flow　rate　can　rarely　affect　the　types　of　oxidation　products　from　XRD　analysis.　Meanwhile,　the　R-depth　of　316　L　specimens　is　58.1%　lower　than　that　of　304　specimens　at　2　m/s　in　QNN　salts-based　nanofluids　after　1000　h　test.　This　work　could　provide　basic　dynamic　corrosion　data　for　design　and　operation　of　concentrated　solar　power　plants.