Calcium hydroxide was reacted with aliphatic calboxylic acids having the different number of carbons, and the precipitated products were characterized by TG, SEM, TEM and XRD. Layered structure was confirmed by TEM images and XRD patterns. From the results of XRD patterns, the interlayer spacing d increased with an increase of the number of carbons of carboxylic acids from 30 Å to 60 Å, and it was proportional to the carbon number of the materials. Calculated angles of the long chain fatty acids in the crystal structures of the reaction products was about sixty degrees. The adsorption ability of the nanocomposite prepared with stearic acid was carried out by using the mixture of three organic compounds at room temperature. For the adsorption experiment, only one kind of organic matters was selectively adsorbed.