Municipal solid waste incineration bottom ash (IBA) contains metallic aluminum which could generate hydrogen gas and lead to the occurrence of concrete crack when IBA is used in cement matrix.In this paper,IBA was pre-treated with alkaline solution, i.e.sodium hydroxide solution or calcium hydroxide solution, under certain conditions.The alkali treatment effect on metallic aluminum removal, chemical composition of IBA,compressive strength as well as strength activity index (SAI) of cement-IBA mortar and heavy metal immobilization in IBA was presented.The results showed that metallic aluminum in IBA could be completely removed by treatment with sodium hydroxide solution, and the alkali treatment did not change the major components of IBA though some aluminum compounds changed.From the compressive strength of cement-IBA mortar, it showed some pozzolanic property of IBA could sacrifice when IBA is treated with alkaline solution.However, the SAI value of cement-IBA mortar using IBA treated with sodium hydroxide solution under low temperature and low PH can still reach more than 80%, which is meaningful in practical application.Alkali treatment can also benefit heavy metal immobilization in IBA.In general, this paper revealed a viable way to treat incineration bottom ash (IBA) to be suitable for supplementary cementitious material application.