This study focuses on the comparison of surface and oleic acid adsorption characteristics of calcium, magnesium, barium, zinc and aluminum silicates produced from the same rice hull ash. The chemical compositions of calcium, magnesium and zinc silicates were analyzed as 45-49 % SiO2 and 13-14 % M-O (Ca, Mg, and Zn). Surface areas were measured to be 625, 309, 141, 84 and 60 m(2)/g for Mg, AI, Ca, Ba and Zn silicates, respectively. Although magnesium silicate was observed to have the highest surface area, its oleic acid adsorption capacity was not as high as that of calcium silicate, which was measured to be 506 mg oleic acid/g adsorbent. This value was 126 mg oleic acid/g adsorbent for magnesium silicate under the same conditions.