The catalyzing carbonization function of alpha-zirconium phosphate (-Zr(HPO4)(2)H2O, -ZrP) based acrylonitrile-butadiene-styrene copolymer (ABS) is studied. Structure and morphology of the organophilic alpha-zirconium phosphate (OZrP)/ABS nanocomposites via melting interaction are characterized by X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). The results indicate that a nanostructure is formed. The thermal stability of OZrP/ABS nanocomposites is investigated by thermogravimetric analysis (TGA). It is found that there is a transformation of the char microstructure in the ABS matrix with the OZrP. Morphology and structure (HRTEM and SAED) investigation distinctly show us the presence of graphite sheets and carbon nanotubes (CNTs) in the chars. Based on this found, a possible and reasonable mechanism of catalyzing carbonization is given in the discussion. (c) 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3038-3042, 2013