Objective: In order to improve the drug loading, the acid-montmorillonite as the carrier of S( )-ibuprofen, and prepared S( )-ibuprofen/acid-modified montmorillonite complexes, to explore the drug compounds release law in different pH values. Methods: The montmorillonite was treated by different concentrations of hydrochloric acid (5%~20%), and characterized by powder XRD, BET, SEM and so on. The effects of the pH of release media on in vitro release of the S( )-ibuprofen were assessed by a dialysis method. Results: The acid concentration of 15%, the specific surface area of montmorillonite is maximum 246 m2/g, and the drug-loading has increased to 352.4mg2/g. In vitro release experiments showed that the cumulative release percentage amounts of the composite effect of pH, In the artificial gastric juice (pH 1.2) and in the artificial intestinal juice (pH 6.8) , the in vitro cumulative amount of the composites were respectively, 18.6 % and 89.3 %. Conclusion: Acid-treatement can improve the drug-loading, and the drug compounds has pH response and sustained-release behavior. This composites is expected to be sustained-release and intestinal oral preparation.