In this paper, the corrosion behavior was researched which was happen on the 304,321,316Lect. stainless steel materials in the analogue situation of calcining gas atmosphere of ammonium paramolybdate.The oxidized etch which happened on the sample’s surface, phase constituent and element content of the fracture surface, was analyzed by the means of SEM、XRD.The results showed that the phases of Fe2(MoO4)3,MoO3,MoO2.5(OH)0.5,Cr2O3,Cr2Ti5O13, Fe2O3,Fe3O4 ect. are contained on the surfaces of the 304,316L, 321 samples which are calcined. There is an inside oxidized corrosion layer in 304 316L. The oxidizing film is damaged and the oxygen penetrates into the base to form an oxidized layer. A thin and compact oxidation film was formed between 321 corrosion layer and the alloy interface, which have prevented the base from further corrosion, under this experiment conditions, this steel belonged to the inoxidizability materials. The coating deficiency of 321 steel is shallow; the particles of oxidate is thin and without inner corrosion; the weight gain rate of oxidized etch is slow (average rate 5.2×10-2mg/ (cm2•h)), the weight gain is less and corrosion resistance is fine.