The styrene butadiene rubber (SBR)-clay nanocompounds were prepared by the latex compounding method, and then hexadecyl trimethyl ammonium bromide (C16) and 3-aminopropyl triethoxy silane (KH550) were added into these nanocompounds on a two-roll mill to prepare nanocomposites with strong interfacial interaction. The structure and properties of SBR-clay nanocomposites were carefully studied by X-ray diffraction (XRD) studies, transmission electron microscopy (TEM), Rubber Process Analyzer (RPA), and mechanical testing. Compared with unmodified nanocomposites, the dispersion structure of modified SBR-clay nanocomposites is better with part rubber-intercalated or part modifier-intercalated structure. The tensile strength and the modulus at 300% elongation of modified SBR-clay nanocomposites are higher than three times of those of unmodified nanocomposites, respectively. (c) 2006 Wiley Periodicals, Inc.