Abstract: The effect of five kinds of nano particles Al₂O₃, CuO, ZnO, TiO₂ and SnO₂ in simulated molten solar salt on corrosion of 304 stainless steel used as solar salt storage tank material was studied by corrosion weight gain method and surface analysis technology. The results showed that all the 304 stainless steel samples immersed in molten solar salt with or without nano particles had corrosion and weight gain. The addition of Al₂O₃, CuO, ZnO, TiO₂ and SnO₂ nano particles could inhibit the corrosion of 304 stainless steel, and the inhibition effect rank was Al₂O₃, ZnO, CuO, TiO₂ and SnO₂ in turn. In molten solar salt, the nano metal oxide particles could form a good protective film on the stainless steel surface. In addition to forming physical doping with nano particles on the stainless steel surface oxide layer, chemical doping was a more important factor.