Corrosion of devices and pipes in refinery and petrochemical plants cause problems like deterioration of process efficiency and equipment reliability etc Hence, a suitable technology is required to prevent accident caused by corrosion and raise process efficiency by forecasting the degree of corrosion. The corrosion problems on the top of the distillation column are more serious due to corrosive substances like hydrogen sulfide and chlorine etc. Therefore, in this study, corrosion rate was forecasted and applied through analysis of the corrosion Mechanism on the top of refinery distillation,column and the validity of the model was checked using the actual data considering interference effect caused by competitive reactions between caustic substances. The four components that affect corrosion the most, H2S, CO2, H+, and Cl-, were selected through analysis of the mechanism of corrosion on the top of refinery distillation tower. The model for the analysis of corrosion mechanism was analyzed in the viewpoint of transport phenomenon and reaction engineering, and parameters were estimated with the use of least-squares method.