Early　properties,　reaction　products,　chemical　bonds　and　structural　units　of　alkali-activated　brick　powder　geopolymers　(BPG)　are　studied　by　measurement　of　compressive　strength,　and　by　techniques　of　XRD,　TG,　FTIR　and　Si-29　MAS　NMR　taking　curing　humidity　as　variable.　The　results　show　that　the　optimum　compressive　strength　of　BPG　can　reach　67.8　MPa　with　curing　humidity　of　60%,　curing　temperature　of　70　C　and　curing　age　of　3d,　while　the　high　curing　humidity　(RH:　85%　or　95%)　is　unfavorable　to　the　strength　development　of　BPG.　Microscopic　test　results　show　that　increasing　curing　humidity　(for　mixes　cured　up　to　＜　60%　RH)　causes　the　increases　in　chemically　bound　water　and　Al-rich　structural　units　(Q(4)(3Al)　and　Q(4)(4Al))　resulting　in　the　excellent　compressive　strength.　However,　high　curing　humidity　(RH:　95%)　reduces　the　chemically　bound　water　and　hinders　the　formation　of　Al-rich　structural　units　(Q(4)(3Al)　and　Q(4)(4Al))　resulting　in　the　poor　compressive　strength.　The　reduction　in　physically　bound　water　is　favorable　to　the　strength　development　of　BPG　when　the　chemically　bound　water　is　comparable.　This　research　work　suggests　that　the　relatively　optimum　silicate　modulus,　alkali　dosage　and　curing　humidity　for　the　preparation　of　BPG　are　1.6,　6%　and　60%,　respectively.