Abstract: 446 ferritic stainless steel containing 0.20wt% Nb was prepared by vacuum melting, homogenization annealing at 1 150 ℃, hot rolling at 1 000 ℃ and annealing at 950 ℃. The effect of hot rolling deformation （20%, 40%, 60%） on microstructure and molten aluminum corrosion resistance was investigated. The results show that with increasing hot rolling deformation, the grain size of the test steel was significantly refined, the location of the precipitates changed from grain boundaries to grain boundaries and within grains, and the content of low-angle grain boundaries first increased and then decreased. When the hot rolling deformation was 40%, the proportion of low-angle grain boundaries was the highest, reaching 27.2%. The precipitates was mainly composed of TiN and （Ti, Nb） C at 20% hot rolling deformation, and was mainly of （Ti, Nb）（C, N）, （Ti, Nb）C and Fe₂Nb at 40% and 60% hot rolling deformation. The content of Fe₂Nb phase at 60% hot rolling deformation was higher than that at 40% hot rolling deformation. With the increase of hot rolling deformation, the thickness of the intermetallic compound layer formed on surface of the test steel after etching in molten aluminum at 770 ℃ for 1 h first decreased and then increased. When the hot rolling deformation was 40%, the thickness of the intermetallic compound layer was the smallest, which was 54.04 μm, and there were dispersed （Ti, Nb）C precipitates in the intermetallic compound layer; the test steel had the most excellent resistance to molten aluminum corrosion.