A new approach was developed to prepare high-performance isobutylene-isoprene rubber/swollen organoclay nanocomposites by shear mixing.Compared with traditional melt compounding method,better dispersion of nanoclay layers in rubber matrix was verified through transmission electron microscopy(TEM) and X-ray diffraction(XRD).The nanocomposites also exhibit significantly improved mechanical properties and gas barrier property.As a mechanism,the molecules of organic swelling agent play a vital role in accelerating the diffusion and intercalation of the matrix molecules.