In this study, we focused on the combination of blast furnace slag mixed cement that imparts alkalinity, and nitrite that has proven in rust prevention treatment method of reinforced concrete. Also influence of these compositions on rust prevention of iron and verified the mechanism was dissassed.In order to observe the influence of alkaline powder and nitrite on iron, iron plates were immersed in aqueous solutions in which these additives were added as model samples. XPS analyses of the surface of iron plate immersed for 14 days, revealed that a large amount of adsorbed oxygen considered to nitrite ion was existed on the iron surface of the sample treated in containing nitrite.As for the energy state of iron, only the test piece containing nitrite ion showed lower peak, suggesting the adsorption of nitrite ion to the iron surface.In the actual steel sheet sample, an intermediate layer was composed of mainly iron and oxygen was confirmed at the interface between under coat containing nitrite and steel plate.