The nanocomposites of nitrile-butadiene rubber (NBR) and organo-montmorillonite modified by hexadecyltrimethyl ammonium bromide (HMMT) were prepared by the reactive mixing intercalation method in the presence of the resorcinol and hexamethylenetetramine complex (RH). The structure of the NBR-RH-HMMT nanocomposites was characterized by XRD, TEM, FTIR, determination of crosslinking density, and so on. The results showed that the d-spacing of HMMT increased Substantially with RH addition and the layers of HMMT were dispersed in rubber matrix on a nanoeter scale. The mechanical properties of the NBR-RH-HMMT nanocomposites were far Superior to those of NBR-HMMT composites, and the glass transition temperature of NBR-RH-HMMT nanocomposite was higher than that of NBR. The reactive mixing intercalation method by introducing RH could enhance the interface combination between the rubber and the organoclay through the interactions of RH with NBR and modified clay. (c) 2006 Wiley Periodicals, Inc.