In　this　study,　both　micro　and　macro　tests　were　performed　to　investigate　the　effect　of　activator　types　on　the　characteristics　of　the　interfacial　transition　zone　(ITZ)　in　alkali-activated　slag　concrete　(AASC)　with　presoaked　ceramsite.　Two　types　of　chemical　activators　(Na2SO4　and　Na2SO4　plus　water　glass)　were　used,　each　leading　to　unique　cement　products.　Microhardness　was　measured　within　ITZ　and　analyzed　together　with　microstructure　observations　by　scanning　electron　microscopy　(SEM).　Macroscopic　properties,　including　compressive　strength　and　splitting　tensile　strength,　were　also　measured.　For　the　AASCs　with　natural　coarse　aggregate　and　ceramsite　activated　by　Na2SO4,　the　microhardness　and　the　Ca/Si　ratio　of　the　ITZ　are　lower　than　that　of　portland-cement　concrete　(PC).　For　the　natural　coarse　aggregate-AASC　activated　by　Na2SO4　plus　water　glass,　the　microhardness　of　the　ITZ　is　higher　than　that　of　PC,　and　the　Ca/Si　ratio　of　the　ITZ　is　lower　than　that　of　PC;　replacing　natural　coarse　aggregate　with　ceramsite,　the　microhardness　of　the　ITZ　improves　further.