Synthetic aluminum silicate was prepared by reacting aluminum sulfate solution with Sodium silicate solution in this study. The optimum synthesis conditions based on the yield of the product were established by applying Box-Wilson experimental design. The results were found to be as follows; Reactant temperature : 50∼72$^{circ}C$, Concentration of two reactants : 10∼17.6％, Mole ratio of two reactants, [Sod. silicate]/[Al. sulfate) : 4.6∼5.0, Temperature of washing water : 25∼4$0^{circ}C$, and Drying temperature of product : 50∼$65^{circ}C$. The physical and chemical properties of synthetic aluminum silicate as medicine were investigated by means of chemical analysis, adsorption test and acid consuming capacity measurements.