Abstract: Iron suffered low temperature hot corrosion (LTHC) in the presence of salt deposits of Na2SO4,Na2SO4 mixed with NaCl and Na2SO4 mixed with V2O5 in a combustion gas at 600℃. The additions of NaCl to Na2SO4 and of V2O5 to Na2SO4 changed the corrosion kinetics significantly and modified the scale structure markedly It is proposed that trivalent iron ions were more favored than divalent ions in the eutectic responsible for the occurrence of LTHC when NaCl was present, while the reaction between Na2SO4 mixed with V2O5 and the gas formed (Na2O)xV2O4(V2O5)6-x providing directly the liquid required by LTHC. The suphide formation in the inner FeO larer was related to the sites of the reduction step wher SO2 was released.