The optimum reaction conditions for the acid consuming capacity of aluminum silicate synthesized from the reaction of sodium silicate solution and potassium aluminum sulfate solution were investigated by Box-Wilson experimental design, and the micromeritic properties were examined by the means of BET $N_2$ adsorption, Hg penetrometer and methylen blue adsorption. The chemical composition of the samples were analyzed by gravitic method. The results were found to be as follows: optimum reaction temperature $54.7^{circ}C$, both concentrations of reactant soln 15.7%, reactants molar ratio (Al/Si) 0.5 and drying temperature $65.0^{circ}C$. The acid consuming capacity of the sample prepared by above optimum conditions was 68 ml and the chemical composition was $Al_2O_3{cdot}3.6SiO_2{cdot}3H_2O$. The relationship between acid consuming capacity and micromeritic properties could not found in the range of experiments. Therefore, it is assumed that the acid consuming mechanism of aluminum silicate depends on the neutralization of $Al_2O_3$ and buffer action of $SiO_2$ in sample.