The melt of smelting reduction with iron bath Possessed high oxidizability andlow basicity. This paper studied the erosion rate and extent of molten slag and iron on different kindsrefractories and the micro-structure changing.It was shown that the main factor of corrosion liningwas the reaction between melt and oxide existing in lining.The serious zone was the interfacebetween slag and iron bath and slag surface. The greater the concentration of iron oxide,the higherthe erosion rate is.So is the temperature.