Lithium aluminum silicate (LAS) was prepared using :he sol-gel technique and starting from LiCI H2O, Al(NO3)3 and Tetraethyl ortho silicate (TEOS). The final product Li20 : A1203 : 3SiO2. Ac id catalysis was applied by using of HNO3, 113PO4 or HC1O4 in addition 1.) a catalyst free sample. Microwave heatitg was employed in both the hydrolysis, condemiation and drying processes. The prepared samples were thermally analyzed by thermogravemetric analysis (TGA) and scanning electron microscope (SEM). TGA thermograms showed sharp decrease in weight at 250°c that varied with the catalyst. SEM analysis also indicated variable shapes of the crystals with different catalysts.