This work reports the selective preparation of different kinds of carbon nanomaterials through carbonization of polymethacrylate (PMA)/organophilic clay (Oclay) composite by just changing the catalyst precursors. The morphologies and structures of the carbon materials were characterized by Scanning and Transmission electron microscopy, X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The result indicated that the catalyst precusors had a strong influence on the morphologies and yields of the obtained products. Carbon nanoflakes were produced when iron oxide was used as the catalyst precursor, cobalt oxide favored the formation of carbon nanospheres, while carbon nanotubes occurred over nickel oxide. The presence of Oclay plallets was determined to prevent the pyrolytic carbon species of PMA in the system from escaping, thus relatively more carbon nanomaterials were obtained. Based on the experimental observations, a possible mechanism was discussed for illustrating the growth process. (C) 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1029-1037, 2013