Nanocomposite powders of carbon nanotubes (CNTs) and montmorillonite (MMT) were successfully synthesized by heating the mixed composites of polypropylene, nickel (Ni) catalyst, and organic-modified montmorillonite in large quantities after the Ni catalysts were removed. Transmission electron microscopy, X-ray diffraction, thermogravimetric analysis, Raman spectroscopy, and scanning electron microscopy show the co-presence of CNTs and MMT. The interlayer distance of MMT was enlarged because of the CNTs, which result in MMT being partly exfoliated and buried in the CNTs. These current nanocomposite powders of CNTs and MMT with superstructure are therefore expected to be ideal fillers for high-performance polymer nanocomposites.