Abstract: CsMMT composites were prepared by solution method, and a new drug sustainedrelease system,AspMMTCs microspheres were synthesized by inverse suspension polymerization. FTIR and SEM were applied to characterize the structure and morphology of the obtained CsMMT composites and AspMMTCs microspheres. Orthogonal experiment was designed to optimize the preparation process of the AspMMTCs microspheres. And in vitro release experiments were used to determine the release law of the sustainedrelease system. Results show that the obtained microspheres assumed a better sphericity and a more uniformly particle size distribution compared with pure Cs microspheres. The drugloaded microspheres prepared by the optimum conditions exhibit 81.20 μm average particle size, 9.61% drug loading and 76.78% encapsulation rate. Aspirin sustainedrelease system is pHsensitive and tends to show a larger release percentage in the phosphate buffer.