By using Eriochrome Cyanine R modified anion-exchange resin as solid phase extraction cartridge coupled with ICP-AES, a novel method for the determination of Al fractionation in soil extracts has been developed. The proposed method possesses the following distinct advantages: (1) Good selectivity. The Eriochrome Cyanine R modified resin shows good recognizing ability for Al fractions. The total monomeric Al-a can be adsorbed on the modified resin in the pH range of 6 similar to 10 by column procedure, and the organic monomeric Al. can be determined by batch procedure rapidly while no adsorption of inorganic monomeric Al-i was found in 30 min at least. Thus Ali can be obtained by subtraction between Ala and Al-o. Major matrix's interference (Fe, Mn and organic substances) in soil extracts can be avoided. (2) Simple manipulation. The modified resin is very easy to prepare just simply by impregnating the resin with a solution containing Eriochrome Cyanine R. This method has been applied to the determination of five fractions of Al in soil extracts with the experimental results being in agreement with those obtained by Driscoll's method. In addition, Calcon, 8-hydroxyquinoline-5-sulfonic acid, Tiron, Solochrome Violet RS, Pyrocatechol Violet, Xylenol orange, Ferron and Alizarin Red S are also modified to anion-exchange resin as solid-phase extractants. Their conditions to pre-concentrate and determine Al fractionation are investigated, and the adsorptive characteristics of various chelating reagents have been discussed and compared.