Recently，hot metal pretreatment processes including desiliconization，desulfurization and dephosphorization have been established as one of the steel making process．And Al2O3－SiC－C bricks or MgO－C bricks are developed and used as lining materials for pretreatment vessels． But，wear mechanisms of these carbon containing bricks are very different by the kind of treatment agents．
In this report，the wear mechanism of the containing carbon was investigated and follwing results were clarified．
1） Soda ash based agents react on the carbon as stronger corrosives than line based agents．
2） Al2O3－SiC－C bricks are more stable against soda ash based corrosives than MgO－C bricks．Na2O reacts on Al2O3 and produces stable β-Al2O3 at the surface，so that Na2O can’t penetrate into Al2O3－SiC－C bricks．On the contrary，as for MgO－C，Na2O reacts only upon carbon and penetrate deeply into MgO－C bricks because MgO causes no reaction against Na2O．
3） CaO based agents act as a weaker oxidant against carbon than Na2O based agents．And MgO is more stable than Al2O3 against CaO based corrosives．
