Poly(methyl methacrylate) (PMMA) was bonded on the surface of attapulgite (ATP) by using an ammonium persulfate amine redox initiation system via grafting from approach. ATP was modified with (3-aminopropyl)triethoxysilane to anchor amine groups on the surface, and then the amine-functionalized ATP was further treated with methacryloyl chloride and 4,4′-azobis(4-cyanovaleric acid) to give methacryl- and azo-functionalized ATP, respectively. Subsequently, surface-initiated graft polymerization of MMA in a soap-free emulsion was performed to afford ATP/PMMA hybrids. Meanwhile, graft polymerizations on the surface of methacryl- and azo-functionalized ATP were carried out for comparison. The grafting of PMMA on the surface of ATP was characterized by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis (TGA). The crystal structure of hybrids was characterized by X-ray diffraction analysis. The morphology of hybrids was observed by scanning electron microscopy and transmission electron microscopy. The degree of grafting obtained from surface-initiated graft polymerization in a soap-free emulsion was found to be the greatest (29.4%) estimated from TGA. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41062.