This paper reports on the preparation of porous membranes consisting of plate-like beta aEuro(3)-alumina grains and the evaluation for microfiltration properties. Porous beta aEuro(3)-alumina-based ceramics were prepared by the solid-state reactive sintering of Na2CO3 and alpha-Al2O3 at 1100-1300 A degrees C. To study the effect of impurities in the starting powder mixtures, LiF-doped membranes were also prepared. As for the water filtration test, the turbidity before and after the vacuum filtration was measured using sintered porous membranes. To simulate bacteria-contaminated water, a suspension of a commercial boehmite powder (D (50) = 0.7 mu m) in distilled water was used. The non-doped samples sintered at 1200 A degrees C were composed of beta aEuro(3)-alumina (84 wt%) and beta-alumina (16 wt%) grains and showed a good microfiltration performance; the turbidities before and after filtration were 894.4 NTU and 1.46 NTU, respectively.