Na + -beta-aluminas in ternary Na 2 O–Al 2 O 3 –Li 2 O systems were synthesized by infiltration of alkali molten salts into porous α-Al 2 O 3 pre-form. The effects of calcination temperature, infiltration time, and starting materials on phase formation were investigated. Pre-forms were fabricated by pressureless powder packing (PLPP), slip casting, and cold isostatic pressing (CIP) with fused and calcined α-Al 2 O 3 powder. They were heated and infiltrated by alkali molten salts at [Na 2 O]:[Al 2 O 3 ]=1:5 (Li 2 O=0.4 w/o). Each infiltrated specimen was calcined at 1100–1300°C to form Na + -beta-aluminas, whose crystalline formations, phase fractions, and alkali ion contents were analyzed. The pre-form prepared by PLPP with 1μm-calcined α-Al 2 O 3 powder showed the highest Na-β″-Al 2 O 3 phase fraction (59.5%), without residual α-Al 2 O 3 phase.